TH

THE OCARINA.

instrument, the eight holes on that side being
stopped or opened by the fingers when the in-
side are left to the thumbs.
strument is played, and two holes on the other
The tube forming
portion of the circumference of a hole that is
the mouthpiece terminates in a slit around a

an arrangement and mode of attachment the violence down to the rest (every grindstone should be surface of one side of the zinc plate would not HE world must be sadly in want of a greater to injury by being caught between the rest and the provided with a rest), and rendering them very liable be so fully available for the desired action; as variety of musical wind instruments if stone. In determining upon which side of the stone it will be observed that when the zinc plates are secured to studs a large exposed surface of we may judge from the fact that Mr. Thomas any given tool should be ground the workman takes zinc is obtained, although only a small amount Zach, of Vienna, thought it worth while to pay into consideration the following: the shape of the of zinc is used. It must be borne in mind that the preliminary fees for protecting the inven- tool, the amount of metal requiring to be ground off, the protection afforded depends upon the extent tion shown in the annexed engraving. The and the condition of the grindstone. "ocarina" received "provisional protection Upon the edge of a tool which last receives the of the zinc surface, and not upon the quantity only," so that full details of its great advan-action of the stone there is always formed what is or bulk of the metal employed. For insuring protection to some stayed sur- its form may be obtained from a glance at the the edge does not separate from the body of the tages are wanting. However, a general idea of termed a feather edge-that is to say, the metal at faces, and where such stays can be conveniently figure, which represents one side of the musical metal, but clings thereto in the form of a fine ragged placed in the boiler, the patentee makes use web, as shown in Fig. 1, in which A represents a of specially constructed stays, to which zinc grindstone running in the direction of the arrow, B, protectors are attached and perfect metallic and C represents a tool. If now we take a point on continuity insured. The long stays as ordinarily the circumference of the stone, as say at F, it should fitted are not suitable for the purpose, because leave contact with the tool at the point of the tool the ends are usually passed through clearing metal at the extreme edge gives way to the denoted by D; instead of doing this, however, the holes in the plates, and are secured by a nut on each side of the plate with a grummet" and putty or other suitable material round the stay and under the nut for making a tight joint, by reason of which, and also by reason of the oxide or scale which is generally attached to the surface of the plates or the stay when the zinc is attached, continuity between the metals is, to say the least, most imperfect, or, at best, very uncertain. He, therefore, faces or lays bare the surface of the plates in immediate contact with the inner nut or both, or taps the always open. The inventor does not furnish holes in the plates, and screws the well-fitting any particulars as to the power and quality of screwed ends of the stays tightly through the the "ocarina," nor does he give its range or clean-tapped holes, which are then nutted and mention its capabilities in the way of chromatic tightly screwed on the outside only, or both. semitones; but he informs us that his "invenIn Fig. 2 one of several methods of clamping tion has for its object a musical wind instruthe zinc plate to the stay is shown in side view ment of a simple and portable construction, and and section. In this instance, to an ordinary easily to be handled." It is preferably formed longitudinal or through stay making proper of clay, and then baked or burnt. By blowing metallic contact with the boiler plates, a casting in at the mouthpiece and opening and closing of zinc, Z, is firmly held by a strap and cotter, the holes with the fingers, a bolt being passed through strap and plate to "tunes may be hold them together. It will be readily under-played." The size of the instrument and the stood that the cotter driven in at the top of the be used as in the flute. The instrument, it number of holes may be varied, and keys may strap insures perfect contact between the stay will be seen, does not impress one favourably and the zinc. The patentee describes many at a first glance, but it will surprise many to that the stone runs very true, and contains no soft

other methods of fixing and placing zinc plates, but the above are sufficient to illustrate the principal details of his improvements.

SEEING THE EARTH GO ROUND. THE directors of the forthcoming Paris Exhibion a large scale, and to demonstrate to "tout le

hear that it is really capable of yielding very
agreeable music, and is not difficult to play.

PRODUCING CUTTING EDGES FOR
TOOLS AND INSTRUMENTS.*

BY JOSHUA ROSE, M.E.

appear to be more

a

monde" that the earth does revolve. The experi- N° mechanical operation can petool to cure
ment depends upon the property of a pendulum to ting edge, and hence it is that very few persons have
keep swinging in the same plane if its support is any idea of the large amount of knowledge as well as
free to move; and if we could set up a suitable the skill that may be displayed in simply sharpening
pendulum at the North Pole, we should see it swing tool. In the first place, to give a tool a suitable cut-
ing round the circle once in twenty-four hours, but ting edge one must thoroughly understand the nature
at the same time we should know that it was the of the material to be cut, and must have had some
earth that was moving, and not the pendulum. At experience in cutting it so as to know what variation
any place not directly over the axis of the earth the to make in the tool to suit the variations in texture,
point of suspension partakes, of course, of the closeness of grain, hardness, &c., which are always
rotation of our planet, and a correction for that to be found in different specimens of the same
movement would have to be made; but, as that can material.
be calculated to a nicety, the demonstration of its
A cutting edge is formed by the line of juncture
correctness afforded by the pendulum would be proof of the two facets at the point of a wedge. The angle
of the rotation of the earth. Foucault's experiment of these two facets one to the other, determined by
was made under the dome of the Pantheon at Paris, considerations of strength, and the shape of each
and it was repeated in America; but the proposed facet is determined either by considerations of
exhibition will carry it out on a larger scale. The strength or of shape. As a rule the harder the
weight of the pendulum to be erected in the Champ material to be cut the more the approach of the two
de Mars will be about 660 pounds, the length of the facets to a right angle one with the other; and so
rod being some 220ft. It will be hung in such a likewise the greater the strength required the nearer
manner that the points of suspension will be free to the facets to a right angle. Thus, while the facets
move, and consequently the pendulum will continue of a graver may stand at an angle of 50°, those of
to swing in the same plane, or nearly so, because the the cutters for a pair of shears or a punching machine
friction of the supports will necessarily exercise will stand at an angle of about 85°, though both may
some effect. The spectator, standing on what be used to cut iron and steel. In this latter case the
appears to be a stationary floor, will notice that the strength being the main consideration, it must be
pendulum changes its line of oscillation as regards obtained at a sacrifice of keenness, whereas, if we
the floor, and if he understands the question to be take the case of a razor or a lance sharpness is the
answered he will know that the floor upon which he main consideration, and strength is disregarded.
stands is being carried round the pendulum by the There are, however, certain considerations in the
rotation of the earth. Professor Tobin, of production of the cutting edge itself, regardless of
Richmond, Kentucky, has recently devised an the angles of the facet, which affect all cutting
improvement on Foucault's apparatus, his pendulum edges, and these considerations it is which we pro-
being hung to a stand about 6ft. high, in such a
manner that the rotation of the earth is shown by
the changed position of an index which moves over
1° of the scale in about six minutes. His pendulum
is moreover so delicately suspended that it maintains
its motion for about twelve hours, and yet can be
retarded, or even stopped, by blowing upon it.

Echo.

Summer Schools of Science.-The ball which was set rolling by the enterprise of the late Professor Agassiz, at Penikese, makes new accretions every year, and the Summer Schools of Science are becoming very numerous,

pose to discuss.

First, then comes the question as to on which side of a stone a tool should be ground, and this depends upon the shape of the tool, the amount of metal requiring to be ground off, and the condition of the grindstone. If the tool is held in such a position that the revolving surface of the stone runs towards the operator, the operation can be performed quicker, and, as a rule, better; but it is in many cases quite dangerous, because the edge of the tool is liable to catch in any soft part or a spot in the stone, and to be dragged from the fingers, carrying them with

* From the Scientific American.

pressure, and does not grind off, but clings to the tool, leaving a web, as shown from D to E, whereas, if the same tool were held in the position shown at G, the point, F, upon the stone would meet the tool at the edge first, and would cut the metal clear away and not leave a feather edge. Now the amount of the feather edge will be greater as the facets forming the edge stand at a greater angle one to another, so that were the facets at a right angle, instead of forming an acute wedge, as shown in Fig. 1, the feather edge would be very short indeed. But in all cases the feather edge is greater upon soft than upon tool is pressed more firmly to the stone; hence the hard metal, and is also greater in proportion as the workman conforms the amount of the pressure to suit the requirements by making it the greatest during the early grinding stage, when the object is to grind away the surplus metal, and the least during the later part of the process, when finishing the cutting edge, and hence he obtains a sharper tool, because whatever feather edge there may be breaks leaving a flat place along the edge. It would seem, off so soon as the tool is placed under cutting duty, then, that faces which can be ground in the position relative to the stone, as shown in Fig. 1, and upon

a

tool of shape similar to that shown in the figure, towards the cutting edge, as shown in Fig. 1, at the should always be ground with the stone running position denoted by G; and so they should, providing

or hard spots of sufficient prominence to cause the

is

cutting edge to catch, which would render the operation dangerous. These unfavourable conditions, however, are always more or less existent under average conditions, and to such an extent as to forbid the holding of the tool to the stone with the amount of pressure necessary to remove a quantity of metal, as is necessary in the earlier stages of the grinding operation. Furthermore, if the edge of the very serious, and entails a great deal of extra tool does catch in the stone the damage to that edge grinding to repair it, and at the same time iacurs a rapid using up of the tool. Another consideration is that it is much easier to hold the tool steady under ordinary circumstances, in the position shown at H than in that shown at G; and with a bad stone it is altogether impracticable to hold it as at G. Here, however, another consideration occurs, in that the surface of a grindstone is rarely level across the width of the perimeter of the stone, unless the stone present is very largely the exception. As a rule the has a truing device attached to the frame, which at face of the stone is made rounding in its width because there is the most wear in the middle, and it is very undesirable to have the stone hollow across. Suppose, for example, that in Fig. 2 we have a stone that is hollow, and in Fig. 3 one that is rounding across the perimeter; then to grind such a tool as is shown in Fig. 1, as, say, a plane blade, we may move it slowly across the width of the stone, and the highest part of the stone will act upon all parts in the width of the blade, but we cannot by any method grind such a tool upon the hollow stone without leaving the cutting edge rounding in its length.

So far, however, we have supposed the stone to have an even surface; but very often this is not the case, and then the operator, no matter which side of the stone he is using, holds the length of the cutting edge of the tool at an angle to the width of the stone, as shown in Fig. 4, placing the tool in the most level part of the grindstone surface. By doing this he effects two objects: first, he obtains a level spot on the stone more readily; and, secondly, he diminishes the formation of a feather edge. The first is because it follows that, in removing a given amount of metal, there will be more abrasion upon the stone in proportion as the operating area of the stone is diminished; hence the workman selects the highest part of the stone whereon he can find s suitable surface, and by moving the tool across the face wears down the asparities while he is roughing out the tool so as to obtain as smooth a surface as possible for finishing process. If be held the tool still instead of giving it lateral motion, it would grind away in undulations or grooves, conforming themselves to those on the abrading surface of the store, and have but very little tendency or effect in level

ing the same. Referring now to the second advan-rest without the intervention of the hand, but such
tage named it will be readily observed that, if he is not the case, because the operator would not have
held the length of the cutting edge in a line with the sufficient control over the tool, and it would almost
revolutions of the stone, there would be no tendency assuredly catch in the stone. By interposing the
to leave a feather edge, except at the corner of the hand between the tool and the rest, the sense of
edge where the stone leaves contact with the tool, feeling is brought into play, guiding the operator
and this would be of little or no consequence. The just how to hold the tool to prevent its catching in
question naturally arises, then-why not grind the the stone, and admonishing the operator when the
tool in that position-that is, in the position relative conditions possess any elements of danger, which
to the stone shown in Fig. 5, which would require become instantly hnown from any difficulty in hold-
a very small flat or smooth space in the width of the ing the tool steady against the grip of the stone or
stone, and would avoid the formation of a feather from a disposition of the upper edge of the tool,
edge? The answer to this is, that it is so difficult which the stone meets, to turn in towards the
to grind the surface of the tool level, as will be seen stone.
in the side view of the operation as shown in Fig. 6, Such are the main principles involved in the art
in which A represents the tool enlarged so as to of tool-grinding, and we may now proceed to make
make the ergraving clear, and from B to C, the some practical applications of them. First, then,
length of the cutting edge. To bring the whole to define the point which distinguishes whether the
length of the cutting edge to bear upon the stone is running to or from you, let A, in Fig. 9,
stone it is necessary to move the tool from C represent a grindstone, and B, C, D, E, and F, tools
to D, and from B to E, as denoted by the dotted held thereon; and if a radial line from the centre of
ares at D, E; and if during this operation the tool the stone forms an obtuse angle with the face of
remains an instant longer in any or either of the the tool which first meets a point on the periphery,
positions indicated by the dotted lines, G, H, a or face of the stone, as it is usually termed, then
hollow spot will be ground upon the tool at the the stone is running from you; while if, on the
point of contact between the stone and the tool; other hand, that face forms an acute angle to the

stone, and the more difficult it is to hold the tool steadily, while the reverse is the case when the stone is running from you; and it follows that as the length of the cutting tool edge is greater, the more difficult it will be to hold the tool in the positions of D, E, or F. Therefore, tools having broad cutting edges formed by acute angles should be ground in the position of B, unless, indeed, the stone is very true and smooth, and has no soft spots, in which case it is permissible to grind them held in a position relative to a radial line of the stone similar to that at E, in Fig. 9; but in this case it is well while holding the tool at that angle to grind it in that part of the circumference of the stone occupied in Fig. 9, by D, or between that and the position occupied by E, so that, should it chance to catch in the stone, it will not drag or force the fingers down to the rest. We may now consider what effect the size of the work has upon the posi tion, relative to the stone, in which it should be ground, by giving a few examples of grinding. In the case of very small articles we may use almost any part of a true stone, because the band has comparatively a thorough control of a small article. To grind the sides of a square bar for any distance extending not more than an inch or so from the end, the position shown in Fig. 7 is correct, and the same position applies to similar work upon a round piece of work, the hand upon the rest serving to steady it, while the other hand causes the object to revolve. In this way the piece can be beld steadily while considerable pressure is applied. To grind the end face of any bar the bar is always placed upon the rest, as shown in Fig 9, at F, int care should be taken to move the bar to various positions along the face of the stone or slowly to revolve it, causing it to travel across that face: otherwise a groove will be worn in the stone. To grind the surface of a bar, it should be held in the position shown in Fig. 4, because, if held square across the stone, it could not be held at all steadily, especially if pressed heavily to the stone. It is highly dangerous to attempt to grind the outside of a bar by placing it on the rest or in any position in which the stone would be running to, or, rather more properly towards you. Any work requiring to be ground to a point must be held in the position shown in Fig. 1, at H, or in that shown in Fig. 7. In the first case, however, it should be moved across the face of the stone, as the grinding proceeds, to prevent the wearing of a groove in the stone. The surface of sheet metal or plates should be ground in the position occupied by D, in Fig. 9. The cutting edges of all blades should be ground in the position shown in Fig. 4, because they can be held steady, and if held lightly towards the finish, with a small amount only of feather edge. All turning and planing tools should have their top faces ground as in Fig. 7, and the other faces as at F, in Fig. 9, because such tools must be held steadily, and require the removal of considerable metal at each grinding. All drills should be ground upon the ends while upon the rest, excepting the faces of flat drills, as at H, in Fig. 1, while the diametrical edges must be ground as in Fig. 7. Anything that is sufficiently long to afford a firm grip with both hands when standing in the position of F, in Fig. 9, may be ground in that position, providing that the top of the rest is close to the perimeter of the stone. All blades requiring a keen edge must be held lightly to the stone, to avoid getting broad and thick feather edges. The edges of blades or plates not required to have a cutting edge, may be ground 1 in the position shown at I, in Fig. 6, or slanted a little, as in Fig. 4.

radial line, then the stone is running from you, no
matter in what position in regard to the stone you
may stand. But common prudence teaches one to
stand as clear of the rest as possible when grinding
with the stone running from you.

furthermore the grinding operation is not very
accessible to the eye, and hence any irregularities
are not very easily corrected. For these reasons it
is impracticable to grind in this position any cut-
ting edge requiring to be a straight line, and having
sufficient length to render much motion in the In ordinary shop parlance, the side of the stone
direction of D, E, a necessity. Furthermore it is on which the face of the stone enters the trough is
very difficult to hold a tool steadily in position always called the side with the stone running to you,
shown in Fig. 6, and as a consequence no satisfac- because all grinding which requires performing
tory result can be attained unless by the aid of a with the stone running to you is performed on that
device whereon to rest the hand; such a device is side, and in conjunction with the use of the rest
called a rest, and is shown in Fig. 7, at A. Now shown at A, in Fig. 7. There is no excuse, and it
suppose we have a tool of the form shown in Fig. 8, is very dangerous, to grind on that side of the stone
requiring to be ground on the faces, A and B, without using the rest as a steadying point, and as
then it is evident that A can only be ground with a safeguard. With the rest, the grinding can be
the body of the steel, C, out of the way of the body more delicately, truly, and accurately, as well as
of the stone, and hence in the position shown in expeditionsly performed, because of the extra force
Fig. 7, in which position the tool may be held with which the tool can be held steadily to the
firmly and pressed firmly to the stone. It is
necessary, however, to rest the hand upon the rest,
and hold the tool exactly in the position shown in
Fig. 7, so that if the tool catches in the stone and
is forced from the hand it will not carry the fingers
with it, and wound them by jamming either against
the stone or the rest, or force them between the two.
It would seem advisable to rest the tool upon the

stone.

In Fig. 9, B and C are ground with the stone running from you; D is neutral, and E and F are ground with the stone running to you. Hence, while with the stone running to you the greater the angle of the front face of the tool that is, the face which has the grindstone running towards it), the greater the liability of the tool to catch in the

After a tool is ground it is often necessary to remove the feather edge without having recourse to an oil stone. Mechanists often accomplish this object by drawing the cutting edge across a piece of wood, holding the cutting edge parallel with the line of motion, which removes the feather edge without breaking it off low down, as would be the case if the length of the cutting edge stood at a right angle to the line of motion.

When a smoother edge than can be produced by the grindstone is required, recourse must be had to the oil-stone. In using the oil-stone it is highly important to keep the facets being stoned level with the face of the stone, but with the surface near the cutting edge of the tool pressed a little the hardest to the stone. Even with the utmost care we cannot avoid forming upon the tool what is termed a wire edge. A wire edge is really a burr formed of the extreme edge of the tool giving way and bending over towards the face not in contact with the stone. To reduce the wire edge as much as possible we press the tool very lightly to the stone during the latter part of the stoning and turn the tool frequently over. If the motion of the tool upon the oil-stone is parallel with the line of cutting edge, the wire edge will be greater than if the line of motion were at a right angle to it.

Again, the strokes performed while the cutting edge is advancing upon the oil-stone produce less wire edge than the return strokes hence the finishing process consists of a few light strokes upon one and then upon the other facet, repeated several times. Now let it be observed that the wire edge will never

ENGLISH MECHANIC AND WORLD OF SCIENCE: No. 668.

be turned towards the facet last oil-stoned, and cannot be obviated by the most delicate use of the stone, but after the stoning proper is finished, the operator will lay one facet quite level with the face of the stone, and then give to the blade, under a very light pressure, forward diagonal motion, and then perform the same operation with the other facet upon the stone, the last facet operated upon being usually the straight and not the bevelled one. To still further reduce the wire edge for very fine work, the operator sometimes uses a piece of leather belt, either glued to a piece of wood, as upon the lid of the oil-stone box, or some attach it at each end to projecting pieces of wood, while yet other lap the tool upon the palm of the hand. In giving an edge to a razor, the process may be carried forward in the usual way by means of straps, the first strokes being long ones made under a slight pressure, the strokes getting shorter and the pressure lighter as the process proceeds, until at last the motion and cantact are scarcely perceptible.

JAN. 11, 1878,

types. The cathedral organ, which requires ponMODERN organs, as designed and constructed, UPON ITS CONSTRUCTION.-II.* derous tone and full volume of sound on account of the large space it has to fill, and the loss of power incident to the spreading of the sound undulations represent one or other of three distinct through the aisles, roof, and transepts. The church organ of smaller dimensions, and of less power from the more circumscribed area of the building, and the concert organ, generally con structed of the first magnitude, with every variety of sound effect, and of immense power and elabo ration of mechanical detail.

The vein, as I have proved by my drifting upon it, short time and indicates only the free sulphuric acid
bas a general strike of N. 73 W., S. 73° E. So added. It is, of course, applicable to limejuice or
far, however, as I have drifted upon it, it runs in a lemonjuice.
zigzag along this general strike. The old excava-
tion commences at a small branch, and runs at a
a gentle slope. The dump material has been thrown
right and left for the first hundred feet. I tunneled
ight angle from it into a ridge that juts down with THE ORGAN, AND SOME REMARKS
branch, and have drifted along it 40ft. Here we
reach an immense dump-rim, 65ft. higher than the
in diagonally, and struck the vein 60ft. from the
level of the branch, and which seems to have been
thrown back upon their works. It forms at this end
a circular rim to the continued excavations higher
up the ridge. The whole length of the excavation
from the branch to the upper end of the cut is about
320ft. The material removed from the upper part
of the cut was carried up the hill as well as down it.
The dump on the upper side of this upper part of
the cut and at the widest point is about 25ft. above
the present bottom of the excavation, and at this
point dump and excavation measure about 150ft.
ANCIENT MICA MINES IN NORTH digging has been carried down about 30ft. below the
across. At the upper end of my tunnel the old
surface. If the excavation at the point just men-
end of the tunnel it would make the dump-heap on
tioned was carried as deep as the work at the upper
the upper side 55ft. higher than the bottom of the
old works. I have been thus particular, in order to
show that with mere stone implements it must have
required a series of years and a large force to have
accomplished such results.

CAROLINA*

metallic substance or ore.

AMONG the remains found in the mounds of the Mississippi Valley mica has been mentioned. While some of it was perhaps used for ornamental purposes and as mirrors, it is a probable conjecture that it was largely used in the religious rites of the mound-building race. or breasts, or over the whole skeletons, had no doubt, That found over the faces attached to it something sacred in the minds of the these old diggings in this county. The vein, as I shall make special mention of but one other of race. The supposition that much of the mica found recently worked by the Messrs. Brooks, yielded in those ancient mounds was employed in the reli excellent mica that was of peculiar interest, because gious ceremonies of the race, suggests the high value it contained in every crystal internal markings in set upon it, and the immense labour employed in pro- deeper and lighter shades of the colouring matter eurig it, as well as the great distance to which it showing the hexagonal form. It has the appearwas transported, sustain the idea that there was more than an economical or commercial value attached to it. mica. I found one crystal in possession of the proance of having been photographed in the plates of Professor Charles Rau suggests that the mica prietors that was revolved upon itself, which, being found in the western mounds was probably obtained split up and adjusted, formed a hexagonal crystal, along the southern spurs of the Alleghanies. This and showed the entire hexagonal in the internal is, I have no doubt, correct. For here we have markings. May we not suppose that such markings ancient diggings which were open excavations. deeply impressed the idolatrous race who used it? Some of these excavations are of large propor- after the mica, and where there is any evidence of tions, and must have employed a large force and a The ancient miners seldom attempted tunneling series of years in their accomplishment. I have not cutting a tunnel. There is one such hole a few miles zeen the slightest trace of mining work for any from Franklin, but it does not exceed 15ft. in length. of such work it is more like burrowing in than number of these ancient excavations, and they were Franklin an old shaft was discovered and opened evidently all made in mining for mica, with a few last spring, at the bottom of which two irons were There are a great In one of the old diggings about four miles from made in soapstone beds, where the aborigines no doubt obtained the material for their stone pots. The Spanish axe, and an iron gad. This work was done, largest of the excavations in steatite which I have perhaps, by De Soto, as his journal leaves us to found, evidently the shanks of a windlass, an old seen are in Tallapoosa County, Alabama. There are infer that he passed through this mountain region. several ancient mica diggings in Mitchell County, Moreover, the pick marks in this old shaft have North Carolina. General T. L. Clingman, some sharp angular outlines which distinguish them from twenty-five or thirty years ago, supposing that these old diggings were the work of De Soto in the blunt marks of the stone implements as seen in search of silver, had one of the old pits opened, and the old diggings. This shaft was assuredly not instead of finding silver, he found a vein containing the work of the race who made the excavations. Jarge crystals of mica. When mica was brought into use among us, and assumed an economic value, subsequent working on the vein settled the question as to the object of the ancient miners. This mine has been a very profitable one. There are several other old diggings in Mitchell County, some of which have been opened, and valuable mica veins found in them. It is manifest that the ancient miners understood their business well. Indeed they seldom committed a mistake. In every instance which has come under my observation where they did work along the mica zone, mica veins have been found by opening the old works. It is also a noteworthy fact that where the old excavations are extensive the viens yield usually large crystals of firm mica of good cleavage, and in every way of excellent quality. The mica that they procured in their mising operations has been removed, except the refuse, such as our people generally reject. I have one case to the contrary. In that case the mica had been taken one hundred feet perhaps, and buried. It was found to the amount of several cart loads. It had been packed down with great regularity in an excavation. In this country (Macon) there are a dozen or more of these old diggings known to exist. Most of them have been opened within the last six or seven years, and operated upon by our present mica miners. I have had two of these old works opened, one of them upon my own farm. I have watched the developements in these ancient excavations with unusual interest, and I think I see very clearly corroborative evidence that the people who did this ancient work had no implements superior to stone. They only operated upon such veins as contain a decomposed and consequently soft feldapar.

I have observed another interesting fact. Whereever there was a hard point in the vein they worked over it, and then descended again. If they had known the use of metallic implements it seems that they would have removed such points. The ancient works on my own farm are the most extensive I have yet seen, and are therefore worthy of description.

By C. D. SMITH, of Franklin, N. C., from the Smithsonian Report.

THE ESTIMATION OF SULPHURIC
ACID IN VINEGAR.*

parts, it will at once be conceded that the organ-
large organ, and the extraordinary combination of
When we examine for a moment the details of a
builder has not only a most difficult task before
him to produce a perfect instrument, but to be
considerable attainments, having an intimate know-
ledge of several of the most important branches of
science-and not only so, but must be able to apply
a master of his profession he must be a man of
his knowledge in the best possible way.

must be at his finger ends.
Mechanics, aconstics, pneumatics, and electricity

of combinations of levers and compound levers,
set in motion by the depression of a key touched
by the finger, and this key has to be adjusted to act
Most of the internal action of the organ consists
with as delicate a touch as possible to enable the
player to perform (both with rapidity and certainty)
its action, and though itself easily depressed, it has,
passages of music. The key must be unerring in
by connection with the levers in the interior of the
organ, to perform work that requires absolute force,
and to overcome inertia, friction, and the resistance
of wind pressure.

insure efficient touch and action. of mechanical power is therefore indispensable to and diameters of his wind conveyances to admit the An intimate aquaintance with the applications proper quantity of air into the pipes, be they close of pneumatics must enable him to adjust the size organs, perhaps some hundred feet away. He must His knowledge to the wind supply, or, as is often the case in large thousand pipes varying from 32ft. to in. in length, or when only one single pipe is sounding, as in the be equally available to sound simultaneously one case of an air played as a "solo" the intonation of be able to calculate this supply of wind, so as to his pipes must be perfect under these two extremes. His knowledge of acoustics must enable him to regulate the scale of his pipes, and the quality of sound they are intended to produce, that he shall be able to draw out from them the sweetest notes and the fullest body of sound, prompt and free from imperfect intonation.

The exigencies of the modern organ frequently require that electricity shall be employed as a conductors, the principles of electro-magnets, insubstitute for the cumbersome internal arrangeduced currents, the generation of the electric passage of currents of electricity through metallic ment of levers and compound levers, and he must current, and the relation of quantity to intensity, be proficient in the general laws which regulate the Sometimes this current of electricity may be divided into forty or fifty parts, according to the number and combination of keys pressed down, each having its special duty to perform; at other times the same current may be only employed as a unit; in either case his coile, electro-magnets, contacts, and acces erring precision. the present day requires to be a man of scientine sory movements must act with certainty and unknowledge, and with the power of properly applying his information to the work he desires to perform. The successful organ-builder of

determination of sulphuric acid in vinegar con
BY W. C. YOUNG, F.C.S.
sist in either estimating the total sulphuric acid as
THE most commonly used for the
sulphate of barium and deducting from it the
amount found as sulphates in the ash, or in taking
the acidity of the vinegar after evaporating the acetic
acid on a water bath. The first of these methods is
open to the objection that all chlorides present are
converted into sulphates, thus taking up part of the
sulphuric acid originally present in the free state.
in driving off the acetic acid without charring some
of the organic matter and consequently forming
In the second method I have found great difficulty
sulphurous acid; in addition, the objection to the
former method applies equally to this, as any hydro-
chloride acid formed by the action of the sulphuric
acid upon the chlorides present would be volatilised.
It occurred to me to take advantage of the decom-
position of chlorides by sulphuric acid to estimate
the quantity present by determining the amount of
hydrochloric acid liberated. This I do in the follow-great measure owing to the very unsatisfactory
ing manner:-To 30 c.c. of the vinegar under nature of the majority of the organs every day
examination is added an excess of chloride of barium, erected in our churches and public institutions that
and the liquid made up to any convenient bulk; in the instrument has so long been unpopular.
There is little doubt but that it has been in a
one-third of the liquid (which is equal to 10 c.c. of
the vinegar) is estimated the total chlorine by
standard solution of nitrate of silver after carefully
neutralising with weak caustic soda solution; the
fully iminerated, and the chlorine in the ash
estimated as before. The difference between the two
remaining two-thirds is evaporated to dryness, care-
results calculated for the same quantity of vinegar
is due to hydrochloric acid volatilised, from which
the sulphuric acid may be deduced by calculation.
I have made many trials of this method and have
obtained uniformly exact resuits: it takes but a

perly constructed, and an organ improperly con-
structed is, without doubt, only an ill-sounding
Without such knowledge, no organ can be pro-
"kist o' whistles."

Read before the Society of Public Analysts on 14th
November, 1577.

comparison; unless you taste good wise you do not realise the meaning of "sour grapes "unless you hear the true organ tone you cannot discriminate The merit of anything can only be recognised by How can it be expected that perfect acoustical instruments can be produced it the builder of the the imperfections of the modern music mill." instrument is ignorant of the fundamental principles of his art? very few of the builders of the present day are wen who have more than the most elementary acquainOrgan-building is a "science, sophical Institution, by Mr. NATHANIEL Delivered before the Edinburgh Literary and Phuhe December, 1877. J. HOLES

" and

tance with the fundamental rules of their art, and the result has been that nine-tenths of the instrum-nts erected at the present time are simply compounds of nails, wood, metal, and glue at 9d. an hour. This, no doubt, is a very grave acensation against our modern organ-constructors.

It will now be understood that organ-building (like painting, poetry, and sculpture) is a delicate art, nay almost an inspiration. Schmidt has never yet been eclipsed in his sweetness and beauty of tone. Mechanical knowledge may have surpassed bim in the accessories of finger touch and suitable wad supply, but for music, his organs, until de stroyed by ruthless hands, were unsurpassed in tone The general construction of the organ may now be considered. It is not intended to enter into organ-building, but only to refer to those salient prints in the art, as regards constructive science, which may be of use in discriminating between an organ and the apology for an organ.

effects.

details such as would enable a novice to commence

The first thing that strikes the observer is the general outline of the case and its magnitude, the keyboards, and the number of the stops or registers. These details all vary according to the size and importance of the instrument.

The number of the keyboards will be found to ranze from one to four; each set of keys should have a compass of five octaves or sixty-one notes. Ia cheap organs the keyboard is often cramped down to G without the F or at most carried up to A. Now, there are many recognised pieces of music which cannot be performed with due justice, unless the compass of the keyboards is extended to five octaves-C C, 8ft., to that of the 3in. pipe of the open diapason-the standard and foundation unit of all organ tone.

The number of the stops may vary from ten to one hundred, distributed over the various keyboards; thus each keyboard will represent a distinct instrument. or rather, a distinct combination of tone. There is the loud organ, usually called the "great organ;" the organ for accompanying the voice, called the "choir organ;" the organ for producing crescendo and diminuendo effects, termed the "swell organ;" and the organ for solo and other recitative music, generally of considerable power and volume of sound; and in very large instruments an echo," or distant organ; and a "carillon" or bell organ is sometimes added.

tion of our architects in sound-propagation and case
designs, is so important that however distasteful it
may be to the profession it is the duty of every
exponent of musical undulations and sound-propa-
gation to plainly point the finger of rebuke to the
shortcomings of the professional men and builders
who deal in stone, brick, timber, and mortar, and
who are chiefly responsible from their ignorance of
the laws of acoustics for the inflictions as regards
musical sounds that are thrust upon long-suffering
congregations the whole year round.
The foundation of every organ is the proper wind
supply. Without wind, although the kya may be
actuated by the fingers, the instrument would be
silent; an insufficient or irregular supply of wind
will mar the effect of the most accurate adjustment
of mechanism, and the musical tone of the pipe.
It is, therefore, necessary that the capacity of the
bellows for producing wind and the size of the wind
chests and reservoirs should be carefully considered
and adjusted to the requirements of the full organ.
How rarely is an organ to be found with an ample
supply of wind! In general, it is impossible to use
the full organ coupled with sustained chords, with-
out the wind becoming unsteady, and the quality
and the fullness of the tone considerably impaired.

In nearly every large instrument, and the majority
of church organs, the wied supply will be found
both insufficient and unsteady. The wind produced
by the action of the bellows is usually conveyed into
one or more large reservoirs, the upper boards of
which are weighted to give the required pressure to
the contained air, which then passes by means of
pipes, called "wind trunks," to a portion of the
organ called "the wind chest." In instruments of
the first magnitude, where the consumption of wind
through the pipes may at times be very large, and
again be reduced to a minimum, it is not unusual to
have the wind at the various pressures conveyed
into a second set of reservoirs placed immediately
under the wind-chest for the purpose of equalising
and steadying the wind under the extremes indicated
Over the wind-chest is placed the soundboard, which
is divided off into a series of long grooves, corre-
sponding in number to the notes of the keyboard.
The spacing of these grooves or partitions is adjusted
to the quantity of wind necessary to give sound to
the particular series of pipes planted upon the upper
board immediately over them. The top of the wind-
cheat is perforated, so as to admit wind into each of
the soundboard grooves; and pallets kept up by
springs close these perforations, shutting off the
entrance of the wind into the soundboard. Each of
these pallets is mechanically connected with its
special note on the keyboard; the depression of a
key by the finger, therefore, opens the pallet, and
the wind is admitted into the grooves of the sound
board. As these pipes extend over nearly five
octaves, and range from 16ft. down to in. in length,
it is evident that the larger scaled pipes will draw
The "carillon," or bell organ in general, is an off more wind than the smaller ones, and a varia-
acoustical effect produced in imitation of hells by tion of pressure will occur in the wind-chest. This
the employment of three ranks of small pipes of unsteadiness of the wind supply to the soundboard
different intonation, the combined effect being is a very prevalent fault, and, as a necessary conse
somewhat similar to the "clang" of bells. It is, quence, the musical intonation of the pipes is
however, impossible to simulate the metallic ring of rendered unpleasant and disagreeable to the ear.
a bell by means of pipes, and in some few instances In every properly constructed organ the wind.chest
bells have been introduced with a brilliant effect. should be divided into two or three air-tight com-
The carillon stop in the great concert organ, partments, each having its special wind supply and
Primrose-bill, London, constructed by the eminent connecting trunk. This obviates any unsteadiness
builders, Bryceson Brothers (the founder of the of intonation when rapid passages of music or abrupt
firm being a contemporary with Snetzler), consists of transitions of tone occur. The modern system of
a gamut of five octaves of bells, sixty-one in number, building organs by the circulation of a specification
the largest sounding the 4ft. C tone. This, at pre-containing a given number of stops, and accepting
sent, is the only perfect "carillon" organ in the
world, and the " cymbal" effect, when combined
with the full organ, connot be described-it must
be heard to be appreciated.

The disposition of the keyboards in a large organ is a matter of considerable importance to the performer. In this small insular island we are very conservative, and the invariable rule has been to perpetuate an error and appropriate the lowest set of keys to the "choir organ," the "great organ" to the second, the swell organ" to the third, and in instruments of the first magnitude the "solo organ to the fourth keyboard.

In addition to the manual organs, the "pedal organ" has to be considered important as giving grandeur and fullness of tone to the instrument. The pedal organ, properly balanced, should carry down the tone of the keyboards an octave lower; the pipes, therefore, appropriated to the pedal bass, are of large size and deep intonation.

This important section of the organ is actuated and caused to sound by the depression of an independent set of keys depressed by the feet, and called the "pedalboard.' In compass the pedalboard generally extends from C C C, 16ft. to F, thirty notes, and it is supplied with its special wind trunks, soundboards, and mechanism.

the wind supply, and improper intonation of the pipes that have been noticed, arise almost entirely from the desire to obtain a large instrument at the lowest possible expenditure of money. The nails, wood, metal, and glue at 9d. the hour-the historical "kist o' whistles."

In order to control the sounding of the various ranks of pipes planted upon the top of the soundboard, its upper surface is pierced with a series of holes, in number corresponding to the pipes standing in the rackboard over each groove. Thin strips of wood, similarly perforated, are placed over the e holes, so as to interpose a wind connection between the soundboard and the wind chest, according as these strips of wood are closed or open. Thus by the backward and forward motion of these sliders the wind is either allowed free passage through the holes, or is cut off entirely, according as these strips or sliders shut off or leave open the exits. Over the soundboard is placed the rackboard, into which the several ranks of pipes are placed.

The foot of each pipe is adjusted to stand over the soundboard holes. When all the sliders are, therefore, drawn, all the wind holes are open, and the pipes sound. When the sliders are shut the wind is cut off, and the pipes are silent.

These sliders are controlled from the stops at the keyboards, each stop representing a slide and rank of pipes.

The question of wind pressure is one of great importance, as the voicing and tone of the pipes is greatly influenced by the elasticity of the air. Too great a pressure overblows the pipe and produces a false tone, all music is lost, and the sound becomes loud and screaming.

The Royal Albert Hall and Alexandra Palace organs are examples of over wird pressure, and of music giving place to noise.

A well-known musician, describing the Albert Hall organ the other day, remarked "Organ, call that an organ! why, it is an American steam devil." To voice an instrument upon an over pressure of wind is a fatal mistake-tone and music give place to noise and sound. Heavy wind pressures are not necessary to produce power and volume of sound. In the great concert organ at Primrose-hill, London, the heaviest pressure is in. of wind on the " solo organ," and tin. upon the "echo organ." This is the lightest known pressure that has been employed in the voicing and intonation of any large organ, yet with remarkable sweetness and musical tone this celebrated instrument produces au almost overpowering volume of sound. Seventy years since how much excitement and bitter feeling was engendered in Scotland by the introduction of the organ, and what a great change has taken place in the musical portion of the service in most of the churches over Scotland! Organs are finding their way into churches and chapels throughout the kingdom, and their aid to the solemnity and beauty of the service is now almost universally acknowledged and accepted; indeed, it is quite refreshing to go back two hundred years and read how much reverence has always been attached to the organ tone. John Mace, of Trinity College, Cambridge, who, in 1644, speaking of the organ constructed by Dallans for York Minster-the instrument destroyed by fire in 1829-makes the following remarks, which are well worth remembering: "Now, here you must take notice that they had then a custom in that church (which I hear not of in any other cathedral which was), that always before the sermon, the whole congregation sang a psalm together with the choir and the organ. And you must also know that there was then a most excellent large, plump, Insty, full-speaking organ. This organ, I say, when the psalm was set before the sermon, being let out into all its fullness of stops, together with the choir began the psalm. But when that vast concording unity of the whole congregational chorus came, as I may say, thundering in, even so as it made the very ground shake under us-oh, the unutterable ravishing soul's delight, in which I was so transported and wrapped up into high contemplation, that there was no room left in my whole mannamely, body, soul, and spirit-for anything below divine and heavenly rapture."

the lowest tender for what may be technically called a paper plan, is fatal to the construction of effective instruments in this country. Cheap watches and cheap organs are equally worthless. Yet such is the general want of information amongst those who require organs and watches that the country builder, with a long pen-and-ink specification, and the advertising watch-manufacturer, generally command the order to the exclusion of the really conscientious workman, who, being master of his craft, cannot lend his name and reputation to other than an instrument of merit. It is not, however, always that the cheapest estimate for the construction of the instrument commands attention. At a city not twenty miles from Edinburgh the highest tender was accepted by the committee, thereby trusting to THE ORIGIN OF THE TELEPHONE. obtain the best organ; but such a proceeding really only points out the prevailing ignorance of musical contributes an interesting paper containing last week's Athenaeum Mr. Wm. Chappell These several organs are usually combined together committees upon the subject of the organ. No to form the complete instrument, and are inclosed amount of money will command an effective and personal recollections of the experiments which within the organ case. perfect instrument, unless the builder of the organ have led to the invention of the telephone. He Thus the magnitude and importance of the instru-is a man elevated beyond the mere attributes of a says:ment is in some degree indicated by the size and carpenter and joiner or metal-worker, as has been contour of the case. This is, however, no rule, in- pointed out already. Organ-building is an art, an smuch as the cases designed by the architects of inspiration. Father Smith would never accept any the present day are simply abortions. contract to build an organ unless he obtained his The case designed for the organ in the public own price, and prepared his own specification of the halls is a disgraceful sham, alike deregatory to the instrument contracted for. Why is it that our mind that could conceive it, and fatal to the reputa- modern organ-builders in this country do not maintion of the builder of the instrument, who is expected tain the same position? Hereafter, this important to hand down to posterity the true intonation of his subject will be entered into more in detail, and the organ pipes. Where is the artist who can gradual decadence of organ-building, resulting from combat with the rigid vibrations of 2in. deals and cheap estimates and comparatively unknown country sham metal pipes? This subject, the proper educa- builders, pointed out. The faults of unsteadiness in

Although Prof. Graham Bell's new version of the steps which led up to the transmission of sounds by the telephone was allowed to pass without comment by the members of the Physical Society, it must not be supposed to have received their assent-neither should it pass unchallenged. They met to hear of the telephone itself, and, although some must have been surprised that the names of Faraday and Wheatstone were dispensed with, and the preliminary steps claimed for a certain Prof. Page, they were disinclined to waste the short time at disposal in such a discussion. In one case, at

by rods without the use of electricity. After him it became so much a matter of common sense that other kinds of sounds could be conveyed with or without the electric wire, that the telephone has always appeared to me as the useful application of a well-known principle, rather than as an absolute novelty.

The Eton system of telegraphic conversation at night is also a case in point. A string, held at a sufficient tension to vibrate, answers the same purpose as a rod. Tie at each end of the string a ring of the size of a large napkin ring, or of the orifice of the mouth, and cover the two rings with bladder to be derived from empty marmalade pots. The telegraph is then complete. The string is to be made to connect two dormitories, and whichever of the inmates desires to commence a conversation will draw it up, and speak with the bladder before his mouth. The bladder will receive the vibrations of the voice, and the string will convey them to the other bladder, where they will be distinctly heard. The answer is returned in a similar manner. Such apparatus was exposed for sale near the Polytechnic Institution not long after her Majesty's visit, and I can but imagine it to have been suggested and probably exemplified by Wheatstone, but I have no certain knowledge. Probably Prof. Pepper or Dr. Bachhoffner could answer the question.