70° F. Oil with a flashing point of 110° F. or above is tested at 90°, 95°, 100°, 104°, 108°, 110°, 112° and 115° F. Oils with a flashing point of 120° F. or above are tested at 100°, 1050, 110°, 115°, 118°, 120°, 122° and 125° F.

The easy supervision of this apparatus renders it possible to execute several tests alongside of one another, and by supplying the necessary connections and contrivances for breaking the current the sparks from several apparatuses in use at the same time can be produced by means of an induction-apparatus.

Like all petroleum testers with open oil-holder, the otherwise very exact Saybolt tester has the defect of giving the flashing point too high. This is readily explained by the escape of vapors, by the warm current of air ascending from the apparatus, and by other accidental movements of the air. A too high flashing point is also obtained if the level of the oil is kept a few millimeters lower. But even by strictly observing the rules accompanying the apparatus, there is a considerable difference in the results with one and the same oil, they amounting according to numerous experiments by Engler to as much as about 35.6° F.

B. Apparatuses with closed oil-holders.

These apparatuses yield more corresponding results, their construction approaching more closely the plan of a lamp. The petroleum is under similiar conditions as in the holder of a lamp, inflammable vapors being gradually evolved which accumulate in the empty portion of the vessel, become mixed with air, and explode when ignited. The results obtained in these apparatuses also correspond better one with another, since the oil vapors are not carried away by the warm current of air. As examples the apparatuses of Tagliabue, Abel, Bernstein, Braun, Engler, Heumann, Victor-Meyer, Haas and Beilstein will here be described.

Tagliabue's closed tester. This tester, Fig. 131, consists of the water-bath A and the petroleum-holder B, both of brass. The latter is provided with a cover, upon which are fixed the hood

C, containing a rectangular opening a, the sliding bar b, for opening or closing the aperture beneath it, and lastly, the thermometer D. There is also an improved form of this tester dif

fering from the first in the arrangement of the cover, which is shown in Fig. 132. In this a a is the cover, with openings under the movable bar b b, by which they are closed; ƒƒ are small openings in bb, closed by the piece e, held up by the spring beneath it. By pressing upon the knob c, the apertures ƒƒ are opened, and the bar b b can be moved by the handle g.

In using this apparatus, the water-bath as well as the oilholder is filled, and the bath is gradually heated by the spirit lamp. When the thermometer reaches a definite temperature, a small flame is introduced through the opening a, into the hood C: and at the same time the bar b, in Fig. 131, is moved

to one side, or, as represented in Fig. 132, the knob is pressed down in order to establish communication with the air by openings b, or ff. The testing is repeated as the temperature rises until the flashing point is reached.

Abel's tester. This apparatus is used in England and, since 1882, has been employed in the official testing of petroleum in Germany. It is shown in Figs. 133, 134, 135, and 136.

It consists of a petroleum holder closed by a cover. This holder is filled with petroleum up to a fixed mark. Through the cover a thermometer passes into the oil. The cover is also provided with openings which can be opened and closed by a sliding bar. The movement of the sliding bar is effected by means of a small mechanism, the flame of a small lamp being, by the same movement, so tipped that it comes opposite to the

opening in the middle of the cover when the sliding bar is drawn back. The flame thus comes each time in contact with the petroleum vapors, but retreats after each contact,

while the openings in the cover are at the same time closed by the sliding bar. This is repeated until the flashing point is reached. G is the brass petroleum-holder with the brass ring

r; K are two knobs for lifting G, and h the mark to which the holder is filled with petroleum. D is the cover, the arrangement of which is shown in Figs. 134, 135, and 136. The circu

lar cover has a prolongation with a pivot for the sliding bar S; below are two small pillars s, and s, for securing the mechanism. As a protection from radiating heat, the prolongation is covered below with ebonite e. Opposite to the prolongation are the opening a, for the reception of the thermometer 1, and alongside of it the strap b for the reception of the small lamp / suspended in two pivots; also a white bead p, 3.75 millimeters in diameter, which serves as a measure for the size of the flame. In the cover D are three rectangular openings 0, 0, 0, which can be brought into correspondence with two openings in the sliding bar S by turning the latter.

The object of the mechanism T is to effect a slow and uniform movement of the sliding-bar D so that the gradual opening of the apertures 02, 03, 0, lasts exactly two seconds, and that the slide-bar S finally returns to its initial position and closes the apertures. W is the water-holder, consisting of two metallic cylinders with flat bottom; the inner cylinder must be of copper, while the outer cylinder, as well as the bottom, may be of brass. The annular space between the two cylinders is closed on top by a copper plate. Hence, the inner cylinder alone remains open on top, so that the petroleum holder G can be placed in it. g is an ebonite ring to prevent the conduction of heat. The cover of the holder Wis further provided with the tubulure a, for the reception of the thermometer t2, further the funnel c for filling W and two brass rings gg. The excess of water is discharged through the pipe y.

U a copper and L a spirit

The scale of

F is the trevet upon which the holder W rests; or brass jacket open below and closed above; lamp secured upon the plate w to one leg of F. the thermometer t, for measuring the temperature of the petroleum, is graduated in 1⁄2 degrees from + 10° to + 35°, while the thermometer t, for the water bath is graduated only in whole degrees from +50° to + 60°, the mark 55° being indicated by a red line. Finally, the tester is provided with a glass pipette for filling the oil-holder with petroleum, and a gauge for controlling the dimensions of the apparatus. The whole is en