OBSERVATIONS FOR FINDING THE DENSITY OF THE QUARTZ WEIGHT. 895 
quartz of the form of a cube of about 2*2 inches, having its edges find angles rounded. 
Its apparent weight in air is intermediate between that of a lb. of platinum and a 
lb. of brass, approaching more nearly to the latter than to the former. 
Weighing of the quartz weight in water. 
The quartz weight, which will be designated by the letter Q, was suspended in 
water, from the right-hand pan of the balance, by a fine copper wire, one end of 
which was fastened to a thicker wire bent round Q in a plane through its centre, 
parallel to a pair of faces of the cube. 7‘23 inches of the suspending wire weighed 
0*96 grain. Hence a portion of the wire corresponding to 100 parts of the scale 
displaced 0*016 grain of water. When the counterpoise in the left-hand pan was in 
equilibrium with the weight A-}-B-J-D-}-G-t-K-l-M-f-S-l-(16)-l-(2)-|-0*l grain in the 
right-hand pan, 100 parts =0*268 grain. Hence when Q is suspended in water 
100 parts =0*284 grain. In the observations of July 15 the suspending wire alone 
immersed to the same depth as when Q was suspended in water £!= 12*7029 grains of 
platinum in air. At the close of these observations the fine wire broke, and was 
replaced. In the observations which followed, the wire alone in water 12*5641 
grains of platinum in air. 
July 15, ISiS. Q and wire in water. In right-hand pan. 
G. 
h. 
gr- 
Scale. 
118-05 
62-85 
3-04 
15-30 
3-05 
21-30 
3-04 
21-45 
3-02 
11-00 
3-02 
17-00 
3-02 
14-00 
118-20 
63-05 
3-04 
20-45 
3-04 
20-40 
3-00 
16-00 
3-00 
13-60 
118-25 
63-30 
3-03 
20-45 
3-02 
19-45 
3-02 
15-50 
3-02 
19*10 
3-02 
19-40 
3-02 
20-30 
118-40 
63-50 
3-00 
17-25 
3-00 
15-70 
3-00 
17-30 
118-22 
63-17 
3-020 
17-71 
Counterpoise balances Q and wire in water (G=118‘40, L=63'17) + 3*0237 grains in air. 
In right-hand pan. 
gr. Scale. 
A + B-|-D-fG-l-K-|-M + S-l-(l6) + 2-68 24-6 
2*64 12-6 
D=18-35, C=18*4, F=761-8, E=20. 2-67 23-2 
2*66 19-2 
2-6625 19-9 
C.poise bal. A-l-B-|-D-l-G-f K-l-M-t- S-t-(l 6) -|- 2*6601 grs. in air (D=18-35, C=18-4, F=761’8, E=20). 
