APPENDIX III.

DIRECTIONS FOR DRAWING THE SAMPLE AND PREPARING IT FOR TESTING IN TROPICAL CLIMATES.

(1) Drawing the Sample.-In all cases the testing officer, or some person duly authorised by him, shall personally superintend the drawing of the sample from an original unopened tin or other vessel.

An opening sufficiently large to admit of the oil being rapidly poured or siphoned from the tin or other vessel shall be made.

Two bottles, each of the capacity of about 40 fluid ounces, are to be filled with the oil. One of these, the contents of which are intended to be preserved for reference in case of need, is to be carefully corked, the cork being well driven home, cut off level with the neck, and melted sealing-wax worked into it. The other bottle may be either stoppered or corked.

(2) Preparing the Sample for Testing.-About 10 fluid ounces of the oil, sufficient for three tests, are transferred from the bottle into which the sample has been drawn to a pint flask or bottle, which is to be immersed in water artificially cooled, until a thermometer, introduced into the oil, indicates a temperature not exceeding 50° F.

DIRECTIONS FOR PREPARING AND USING THE TEST APPARATUS IN TROPICAL CLIMATES.

(3) Preparing the Water-Bath.—The water-bath is filled by pouring water into the funnel until it begins to flow out at the overflow pipe. The temperature of the water at the commencement of each test, as indicated by the long-bulb thermometer, is to be 130° F., and this is attained in the first instance by mixing hot and cold water, either in the bath or in a vessel from which the bath is filled, until the thermometer which is provided for testing the temperature of the water gives the proper indication; or the water is heated by means of a spirit-lamp (which is attached to the stand of the apparatus) until the required temperature is indicated.

(4) Preparing the Test-Lamp.-The test-lamp is fitted with a piece. of cylindrical wick of such thickness that it fills the wick-holder, but may readily be moved to and fro for the purpose of adjusting the size of the flame. In the body of the lamp, upon the wick, which is coiled within it, is placed a small tuft of cotton wool, moistened with petroleum, any oil not absorbed by the wool being removed. When the lamp has been lighted, the wick is adjusted by means of a pair of forceps or a pin, until the flame is the size of the bead fixed on the cover of the oil-cup; should a particular test occupy so long a time that the flame begins to get smaller, through the supply of oil in the lamp becoming exhausted, three or four drops of petroleum are allowed to fall upon the tuft of wool in the lamp from the droppingbottle or pipette provided for the purpose. This can be safely done without interrupting the test.

**

(5) Filling the Oil-Cup.-Before the oil-cup is filled, the lid is to be made ready for being placed upon the cup-i.e., the round-bulb thermometer is to be inserted into the socket (so that the projecting rim of the collar with which it is fitted touches the edge of the socket), and the test-lamp is to be placed in position. The oil-cup, having been previously cooled by placing it bottom downwards in water at a temperature not exceeding 50° F., is now to be rapidly wiped dry, placed on a level surface in a good light, and the oil to be tested is poured in without splashing until its surface is level with the point of the gauge which is fitted in the cup. The lid is then put on the cup at once, and pressed down so that its edge rests on the rim of the cup.

(6) Application of the Test.-The water-bath, with its thermometer in position, is placed in some locality where it is not exposed to currents of air, and where the light is sufficiently subdued to admit of the size of the entire test-flame being compared with that of the bead on the cover. The cup is carefully lifted, without shaking it, and placed in the bath, the test-lamp is lighted, and the clockwork wound up by turning the key.† The thermometer in the oil-cup is now watched, and when the temperature has reached 56° F. the clockwork is set in motion by pressing the trigger

If no flash takes place, the clockwork is at once re-wound, and the trigger pressed at 57° F., and so on at every degree rise of temperature until the flash occurs, or until a temperature of 95° F. has been reached.

If the flash takes place at any temperature below 77° F.,

the *These suggestions will be found of value in the use of the instrument in a temperate climate also.

This refers to the Abel-Pensky apparatus.

temperature at which it occurs is to be recorded. The fresh portions of the sample are then to be successively tested in a similar manner and the results recorded. If no greater difference than 2° F. exists between any two of the three recorded results, each result is to be corrected for atmospheric pressure, as hereafter described, and the average of the three corrected results is the flashing-point of the sample. In the event of there being a greater difference than 2° F. between any two of the results, the series of tests is to be rejected, and a fresh series of three similarly obtained, and so on until a sufficiently concordant series is furnished, when the results are to be corrected and the average taken in the manner already described.

No flash which takes place within 8° of the temperature at which the testing is commenced shall be accepted as the true flashing-point of the sample tested. In the event of a flash occurring at or below 64° when the test is applied in the manner above described, the next testing shall be commenced 10° lower than the temperature at which the flash had been previously obtained—that is to say, at 54° or thereunder, and this procedure shall be continued until the results of three consecutive tests do not show a greater difference than 2°.

If a temperature of 76° F. has been reached without a flash occurring, the application of the test-flame is to be continued until a temperature of 95° F. has been reached. If no flash has occurred up to this point, and if the petroleum is declared to be imported subject to the provisions of the Act, the tests shall not be continued, and the testing officer shall certify that the petroleum has a flashingpoint of over 95° and is not dangerous. But if the petroleum is oil ordinarily used for lubricating purposes, and is declared to have its flashing-point at or above 200°, or is oil to which a notification of the Governor in Executive Council exempting it from the operation of the Act will be applicable in the event of the flashing-point being found to be at or above 120°, the test shall be continued as follows: The oil-cup is to be removed from the water-bath, and the temperature of the water in the water-bath is to be reduced to 95° F. by pouring cold water into the funnel (the hot water escaping by the overflow pipe). The air chamber is then to be filled to a depth of 11⁄2 inch with water at a temperature of about 95° F., the oil-cup is to be replaced in the water-bath, and the spirit-lamp attached to the waterbath is to be lighted and placed underneath. The test-flame is then to be again applied from 96° F., at every degree rise of temperature as indicated by the thermometer in the oil-cup, until a flash takes * The Indian Petroleum Act is here referred to,

place, or until a temperature of 200° F. or 120° F., as the case may be, has been reached. If during this operation the test-flame appears to diminish in size, the lamp is to be replenished in the manner prescribed at (4) without interrupting the test.

If a flash occurs at any temperature between 76° and 200° F. the temperature at which it occurs, subject to correction for atmospheric pressure, is the flashing-point of the sample.

In repeating a test, a fresh sample of oil must always be used, the tested sample being thrown away, and the cup must be wiped dry from any adhering oil, and cooled, as already described, before receiving the fresh sample.

(7) Correction for Atmospheric Pressure.-As the flashing-point of an oil is influenced by changes in atmospheric pressure to an average extent of 1.6° F. for every inch of the barometer, a correction of the observed flashing-point may become necessary. The height of the barometer must, therefore, be determined at the time of making the test for the flashing-point. An aneroid barometer is supplied for this purpose. To facilitate the correction of a flashing-point for pressure a table is appended, giving flashing-points of oils ranging from 65° to 80° F., under pressures ranging from 27 to 31 inches of

mercury.

The table is used in the following manner :

Example.-An oil has given a flashing-point of 71°, the barometer being at 28.6 in.; take the nearest number to 71° in the vertical column headed 28.6. This number is 70-8. Substitute for this the number in the same horizontal line in the column headed 30 (the normal height of the barometer). The substituted number-i.e., the true flashing-point of the oil-is 73°.

* This table will be found in Appendix VIII,