and decline of prices. This statement, however, is principally applicable to mechanically made wood pulp. The price of chemical wood pulp is still in favour of makers, and the mills that produce this article are well employed. Gothenburg is the principal place of export.

WOOD PULP, EKMAN'S PROCESS.

The manufacture of wood pulp by Ekman's making is carried on at Bonne-Nouvelle, in Dieppe. The pulp process for paper is sold to paper mills in France, and mostly used, together with rags, for the manufacture of various kinds of paper. It is said that the pulp not only produces good printing paper, but also that a high class of writing and other superior kinds of paper can be manufactured from it without the addition of rags. The wood from which it is made is the 'usual white wood from Sweden and Norway, or Finland. The first operation is to remove the bark and clean the outside of the wood, which is done by women who have been found more suitable for this work than men. Afterwards the round logs are cut into flat pieces of about 2 inches in thickness. The knots are now, as far as possible, bored out by machinery, but any that remain are cut out by hand. Great attention is paid to cleansing the wood in order to obtain a pulp clean enough for good kinds of paper. The clean wood is fed into a cutting machine which rapidly cuts it up into pieces of about 11 inch in length. A band carries the cut wood to the top of the boiling-house. The boilers are of iron, covered on the inside with lead to protect the iron from action of the sulphurous acids used. The boilers are filled with wood from an opening in the top, and then a liquid containing bi-sulphate of magnesia is poured in to cover the wood. The boiler is then closed with a cover, and boiling is done with steam, the time varying from ten to twelve hours. When the boiling process is finished the steam is blown off, and the pulp forced out through a valve at the bottom of the boiler into a tank with a perforated bottom, to allow all the liquid to drain off. The process used is known as Ekman's sulphite process. The chemicals, a solution of bi-sulphate of magnesia, are prepared by leading the gases from burning sulphur over magnesite, water being admitted at the same time. The magnesite-carbonate of magnesia-is a kind which is found in large quantities in Greece and imported from there. (Indian Agriculturist.)

The translation which follows is forwarded as it is thought that the idea may be useful in some parts of India where irrigation or other water-supply is dependent on raising the waterlevel by a few feet during the drier months of the year. The only indispensable point appears to be a masonry wall crossing the direction of the flow and this may be below the ordinary water-level so as to be unaffected by floods. The system seems to recommend itself by efficiency, cheapness, ease of erection and the readiness with which the material can be stored.

་

S. E. W.

In 1867, having occasion to irrigate some meadow lands, I found myself posed by the following problem" To increase the height of a permanent masonry weir by erecting a temporary structure upon it without tampering with the masonry or driving nails into it." This problem was sufficient to cause me grave consideration, for I had been informed by scientific men that it could not be solved, and moreover I knew that its solution had not been attempted either in theory or practice. I had nothing to support my temporary dam, but the surface of the weir and the water it was desired to retain. Without being discouraged, however, I set to work with, as basis, that law of hydrostatics which fixes the point of and direction of, some of the angles of pressure of a liquid on a surface; and also the laws regulating the equilibrium of a solid body resting on certain fixed points; and after various gropings I arrived at the desired result. This result is attained by

(Translation from the French of Dr. Villeneuve in the "Révue des Eaux et Forêts" of April, 1891.)

inclining the surface of the moveable obstruction to the water in such a manner that the sum of the angles of pressure follows a line which passes inside the points of support of the moveable barrier. The solution of the problem appears to me to be novel both in theory and practice, so that when it has been worked out by the Forest or other scientific departments, the theory may well be extended beyond the humble issue I had in view and perhaps become the basis of a new system regulating the construction of temporary dams and applicable to much larger works, besides resulting in various advantages, economic and otherwise, over the systems now in force. The first application of the system was made to a weir in the river Ignon twenty-two years ago, and this has worked well ever since and is still in good order, so that it may be fairly said that practice has proved the value of my theories and of my system. The drawing below represents a transverse section of the arrangement.

The apparatus consists of iron frames and planks. The former are placed on the top of the weir and at about 5 or more feet apart. The 3 iron bars A, B, C, are welded together, the fourth bar D, being hinged at E, can thus be moved from G to F, in order to facilitate the introduction of the planks. This bar D, is also provided with a hinged collar H, which is furnished with a At one end of the bar A, there is a rigid hook

clamping screw L.

which passes over the face of the masonry weir; at the other end is a pedestal K, of such a height as to rectify the slope of the top of the weir. The object of the bar B, is to support the planks which are placed in the space between B and D, and the bar B, must be fixed at such an angle that the line of pressure of the retained volume of water passes along the arrow I, in the inside of the pedestal K. The whole success of the system depends on the accuracy of this item. The planks, well planed on the edges, should be of such length as to overlap at each end and of breadths convenient to the proposed height of the dam. The iron frames are then placed in the weir in a line and so far apart that the planks may overlap in the spaces between B and D, the planks are inserted, the bar D closed and the collars at H tightened up; it will of course be necessary to insert a plank of the same thickness longitudinally at the terminal frames to make up the space between B and D, where there will be no overlaping planks. So soon as the pressure of the accumulating water is brought to bear on the barrier, it acquires an incredible firmness and stability. Contrary to what would be imagined, the hooks at E, serve only to correct the alignment of the frames and to resist the sudden shock caused by any drifting body brought into contact with the dam; in fact if the hooks be placed quite clear of the masonry, the pressure of the water alone will never drive them home. The temporary Dam constructed by me is about 50 feet long, by 2 feet high; it cost £4 10s. and can be put in working order in 15 minutes by one man.

TROPHIES AND COLLECTIONS FOR THE FOREST SCHOOL.

We venture to make an appeal to the sporting and scientific members of the Forest Department to assist in the embellishment of the walls of the Forest School with Shikar trophies and the improvement of our collections. Our readers probably have heard of the great improvements recently effected in the buildings of the School, which give us besides four large and two small lecture rooms, a fine library room, a large museum of vegetable economy and smaller quarters for Zoology and Geology. In the matter of trophies, many Forest Officers, chiefly those of the N.- W. Provinces and our old students, have presented fine specimens, but there are too many of some kinds and there is too little variety. We have beautiful horns of the sambhar, spotted deer and hog deer and fair specimens of those of some of the wild goats and sheep; but of others we have few or none. We have no

heads or horns of rhinoceros, Ovis Poli, Ovis Karelini, Ovis Brookei, Ovis Blandfordii, Capira œgagrus, Nilgiri ibex, Budorcas taxicolor Persian Gazelle, Tibetan Gazelle, Mithun, Yak, wild Buffalo, and Barasingha, while the Ovis Ammon, Ovis cycloceros, Capra megaceros, Hemitragus jemlaicus, Black buck and Bison are but poorly represented (the names are taken from Sterndale). We have no properly mounted heads of tiger, leopard or others of the cats, of the wild boar, the porcupine, wolf and bear; and we shall be very grateful if Forest officers, especially those of the Himalaya, the South of India and Burma will help us to improve our collection and make our students familiar with, at any rate, the heads of the most important of our forest mammalia. To illustrate comparative osteology, skulls of any mammal, however small, but with the bones and teeth complete, will be most acceptable; we cannot afford space for whole skeletons. Specimens of game birds properly skinned, and stuffed or not, with eggs and nests, will also be a great addition: we cannot hope to have a large ornithological collection, but we aim chiefly at illustrating the game birds and type specimens of the chief families and the large genera. We have a good many snakes, but are ready to receive any specimens, besides lizards, tortoises and turtles that can be spared. As with the birds, so with the insects, we cannot hope to have a large systematic collection of beetles, butterflies, moths etc. but do hope to get together a small type collection of important families and above all to illustrate those species which are useful and detrimental to the forest by exhibiting not only the insects themselves in their different metamorphoses, but also the way in which the good or the damage they do is effected.

In Botany and Geology we are better off than in the department of Zoology. We have a splendid collection of woods and hope soon to bring out lists of what are wanted to complete it, and the herbarium is doing well in N. Indian forms, though still poor in specimens from Burma and the South of India. The collection illustrating forest economy is greatly in want of aidwe require fruits, seeds, gums, fibres and manufactured articles to illustrate the subject and assist in teaching forest utilization, and any help will be most thankfully accepted.

Tools and implements used in forest work in various parts of India will be very acceptable, as will models and pictures of forest works, and photographs of forest scenes. We feel sure that we have only to make this appeal to enlist help from the Department throughout India and obtain aid in making a collection at Dehra Dún worthy of the Department, fit to teach our students how wide is the field of science which a forest officer has to survey, and capable of showing our visitors the extent of the forest resources of this great country.

J. S. G.