OBSERVATIONS FOR FINDING THE DENSITY OF PC No. 3. 
849 
June 11. 100 parts =0*29 grain. 
PC-I-Y. 
26*15 
T-l-C-f-0-68 gr.-l-X. 
26-3 
D= 
14 
PC-fX. 
22*3 
T-i-C-t-O-68 gr.-HY. 
24-0 
23*43 
25-0 
C = 
14 
22*1 
23-2 
23-1 
25-6 
F = 
769-5 
23*9 
23-8 
24-5 
25-0 
E= 
15 
22*62 
24-15 
97*2 
101-9 
90-95 
95*15 
4( PC + Y) 4(T + C + 0-68 gr. + X) - 4*7 pt. 4(PC + X) ^ 4(T + C + 0-68 gr. + Y) - 4-2 pt. 
8PC £!: 8(T+ C) + 5-41864 grains. 
34PC =2: 34(T + C) + 22-93888 grains. 
PCi2:T+C + 0-67526 grain in air (<=14-07, &=769‘66). 
PC No. 3 £5:7000-03375 grains of platinum in air (<=14-07, 6=769-66). 
For PC No. 3, log A= 1'32555. For T+C+0’675 gr., log A= 1*32566. Hence 
t;PC No. 3 =330*79, (t;T+C+0*675). Therefore t;PC No. 3 is greater than 
y(T+C+0*675 gr.) by the volume of 0*09 grain of water, or of 0*00011 grain of air. 
Hence 
PC No. 3=7000*03386 grains. 
Weighing of PC No. 3 in water. 
March 31, 1845. 
PC and hook in water. 
In right-hand pan. 
B. 
C. 
F. 
E. 
gr- 
Scale. 
9*18 
1-00 
27*8 
0-90 
8-8 
9*1 
0-97 
18*5 
0-98 
20-0 
9 
0-98 
21-55 
768*75 
8*8 
0-97 
20-0 
8-95 
8-65 
1-00 
22*8 
768*83 
9 
0-97 
20-6 
0*96 
19*4 
0*96 
19*3 
8-93 
8*84 
0-97 
19*7 
0-97 
18*5 
8-9 
768*8 
9 
0*97 
20-4 
0-97 
21-0 
9*01 
8*74 
768-79 
8*93 
0*9693 
19*88 
Counterpoise in air (C=8-74, F= 768-79, E=8*93) balances PC and hook in water (B=9*01) + 0-9696 gr. in air. 
In right-hand pan. 
gr. Scale. 
T+F-pK-f L + R-|-(l6) + (4)-h(l)-|-0-10 15-9 
0-11 22-75 
0-10 17-3 
0-10 17*9 
0-11 25-2 
0-104 19*81 
Counterpoise balances T-|-F + K + L-l-R + (l6)-|-(4)-l-(l)-f 0-1044 grain. 
PC and h. in w. (B=9*01)£i:T + F-)-K + L-f R-f (16) + (4) -1-0-1348 gr. in air (C= 8-74, F= 768*79, E=8-93). 
