VERIFICATION OF A COPY OF THE IMPERIAL STANDARD YARD. 347 
Date. 
1831. 
Imperial 
Standard Yard. 
From 0 to 36 
on the Royal 
Society’s Scale. 
Difference. 
Difference in 
Inches. 
microm. readings. 
microm. readings 
div. 
inches. 
April 5 
46 
621 
161 
.0007074 
481 
61 
121 
.0005358 
46 
59 | 
131 
.0005787 
43 
59 
16 
.0006860 
P.M. 
32 
451 
13 i 
.0005787 
6 
36 
53 
17 
.0007288 
38 ± 
53 
14 i 
.0006216 
37 
54 
17 
.0007288 
39 
52 
13 
.0005573 
7 
261 
43 
161 
.0007074 
29 
44 
15 
.0006431 
31 
44 
13 
.0005573 
8 
31 
47 
16 
.0006860 
331 
47 
131 
.0005787 
34 
46 
12 
.0005144 
9 
51 
67 
16 
.0006860 
51 
68 
17 
.0007288 
52 
67 
15 
.0006431 
10 
43 
57 
14 
.0006002 
11 
351 
53 § 
18 
.0007717 
36 
54 l 
181 
.0007931 
41 
52 
11 
.0004716 
37 
51 
14 
.0006002 
12 
30 
45 
15 
.0006431 
30 
46 
16 
.0006860 
35 
44 l 
9 § 
.0004072 
30 
44 
14 
.0006002 
13 
39 
55 
16 
.0006860 
371 
5 lj 
14 
.0006002 
36 
50 
14 
.0006002 
14 
17 
29 
12 
.0005144 
16 
271 
111 
.0004930 
7 
18 
11 
.0004716 
15 
86 
1031 
! 7 | 
.0007502 
91 
106 
15 
.0006431 
921 
105 
121 
.0005358 
Mean 
.0006204 
It will be seen in the above Table that the greatest difference between any 
one of the thirty-six comparisons and the mean is less than two ten-thousandths 
of an inch ; the distance from 0 to 36 on the Royal Society’s scale may there- 
fore be considered as equal to 35.99938 inches of the Imperial Standard Yard. 
