Page:Proceedings of the Royal Society of London Vol 1.djvu/480

Rh remains of the hippopotamus, in particular, are so frequent, that in an area of 120 square yards, as many as six tusks of that animal were found along with various others of the bones, tusks, and horns that have been mentioned.

One horn of an ox measured as much as four feet six inches in length, and ﬁve inche in diameter at the base; and the size of this, it is observed, is the more remarkable, as another horn of an ox was found near it, only six inches long; but it is added, that they all appear to have been deposited as mere bones without the ﬂesh; for in no instance have two bones that are connected in the living animal been found together. Although these bones have lost their cohesion. as if perished by lying long in a moist stratum, they do not seem worn in any degree, as would have happened if they had been washed by the sea for any length of time.

The third stratum in this ﬁeld is sandy loam, highly calcareous, containing horns, bones, and teeth of deer and oxen, with snail-shells, and shells of river ﬁsh.

Below this stratum follow the gravel and clay corresponding to those of the other ﬁeld; but as the existence of these has been ascer- tained solely in digging for water, it is not known, by actual exami- nation, whether the organic remains which they may contain are of the same kinds.

Mr. Austin’s object in constructing this apparatus was to impreg- nate ﬂuids with any condensible gas by the aid of compression; and for the sake of preserving them in a state of purity, every part was made, as far as possible, of glass. The retort, in which the air is formed; the reservoir. in which the supply is contained; the straight tube, through which it is conveyed, and which serves as a piston ; the cylinder and barrel of the pump; the receiver, containing the ﬂuid to be impregnated; and the valves that conﬁne it,—are all made of glass, the only exception being the stufﬁng of the piston, for which he names various soft materials that may be advantageously employed.

For the sake of greater simplicity in the construction, all the parts are arranged in the same vertical line. The reservoir at bottom, in which the air is ﬁrst collected, is a large bell, with a perforation at the top, where it is cemented with the glass rod, which serves as a piston. These are ﬁrmly ﬁxed in position; for in this instrument, the condensation is effected by moving the barrel upon the piston, instead of having a ﬁxed barrel with a moveable piston. Accordingly, the receiver, which is attached to the upper extremity of the glass barrel, i carried up and down with it in effecting the condensation.

The great impediment to forming pneumatic instruments of glass