OBSERVATIONS FOR FINDING THE DENSITY OF PC NO. 4. 
853 
Observations for finding the density of PC No. 4. 
Weighing of PC No. 4 in air. 
1845. 
100 parts =0*26 grain. 
PC+Y. 
T+C+O-eSgr.+X. 
PC-fX. 
T+C+068gr.+Y. 
25*25 
25*25 
24*9 
25*8 
25*65 
26*75 
25*5 
26*2 
25*8 
26*6 
25*3 
26*0 
24*9 
25*7 
27*1 
27*1 
24*5 
25*5 
28*8 
26*5 
24*3 
25*0 
27*8 
26*8 
23*8 
23*7 
28*3 
27*9 
23*0 
23*35 D= 12*5 
28*25 
27*55 
22*4 
22*9 C= 12*48 
20*25 
20*7 
21*5 
22*8 F = 752*93 
21-5 
19-3 
20*9 
21*3 E= 13*97 
20*8 
18*7 
20*75 
21*0 
19-3 
20*7 
19-9 
20*6 
21*35 
19-6 
22*0 
24*8 
20*7 
19-6 
21*8 
22*25 
25*5 
23*2 
22*1 
23*3 
25*1 
23*5 
22*35 
22*7 
24*0 
23*55 
22*0 
23*6 
23*5 
22*45 
21*7 
23*0 
2.3*65 
21*9 
435*6 
450*1 
461*6 
447*25 
1 9 (PC + Y) £!: 1 9(T + C + 0-68 gr. + X) - 1 4-5 parts. 1 9(PC + X) ^ 1 9 (T + C + 0-68 gr. + Y) + 1 4- 1 3 parts. 
PC No. 4£bT + C + 0*67999 grain in air (it=12*31, S=751‘68). 
PC No. 4 :£!: 7000*03848 grains of platinum in air (^= 12*51, 6=751*68). 
For PC No. 4, log A =1-32543. For TH-C + 0-680 grain, log A =1-32566. 
yPC No. 4 = 330-88, t;(T+C4-0-68) = 330-70. Therefore t^PC No, 4 is greater than 
t;(T-]-C + 0-680 grain) by the volume of 0-18 grain of water, or of 0-00022 grain of 
air. Hence 
PC No. 4=7000-03870 grains. 
Weighing of PC No. 4 in water. 
March 26, 1845. PC and hook in water. In right-hand pan. 
B. 
c. 
F. 
E. 
gr. 
Scale. 
8*93 
7-5 
759-3 
7-9 
3*00 
21*65 
2*96 
12*5 
8*92 
795 15 
8*0 
2*99 
18*5 
3*00 
21*7 
8-85 
3*00 
22*0 
8'5 
7*85 
759*5 
8*0 
3*00 
21*1 
2*98 
19-5 
2*96 
17*2 
3*00 
21*8 
8*7 
7-67 
759-36 
7-97 
2*9878 
19-55 
Counterpoise in air (C = 7-67, F=759-36, E=7-97) balances PC and hook in water (B=8*7) + 2*9887 gr.in air. 
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