TRANSACTIONS OF THE SECTIONS. 
23 
by makers of applying their improvements to chronometers intended for the navy, 
U ,1 not applying them to those intended for the merchant service, lias doubtless 
wucn from the knowledge, that in the former they would be tested at the Greenwich 
Observatory previous to their being purchased; while in the latter, captains and those 
Aouttn purchase chronometers have, till lately, had no means of testing them, or 
miking themselves acquainted with the advantage of any improvement in the com- 
pnuation ; and now that this great boon is offered them in Liverpool, through the 
I totality of the corporation, the advantage to be derived from it is so little u “ de *' _ 
• ■‘-<1 that but comparatively few avail themselves of it. If some method could be 
«n *«l of disseminating knowledge on this subject amongst captains, shipowners, 
iinl underwriters—all of whom arc deeply interested iu a quick and spcuio passage 
-”i«ly some means would be taken for testing all chronometers in those tempe- 
hdu** to which ships are liable to be exposed at sea previous to their being placed 
'• die hands of captains. By so doing, navigation would be greatly facilitated and 
tendered much more secure ; and the beat method of accomplishing this object is, 
1 think, a subject well-worthy of the consideration of the British Association; for it 
* il be fouud that we are in possession of most undoubted evidence that the rates of 
tamnometers now employed in the merchant service are so much affected by change 
” lf, »perature as to render them very unsafe, and even dangerous instruments, in 
_ of captains who are unacquainted with the facts which I have so im- 
developed in this brief notice. We therefore entertain the hope that more 
llf U(nt an d systematic efforts will speedily be made to diffuse the requisite mforma- 
m amongst ail those who are personally or otherwise interested in these important 
1 . *• which I have now presumed to bring under the uotice of the British As- 
“oalion. 
Table I. 
Showing the change in the daily rate of each of 100 Chronometers, caused by 
changing the temperature from 60 to 40 degrees. 
Refer¬ 
ence No. 
Increase of 
gaining-rate 
ny changing 
the tempera, 
turc from 60 
o 40 degrees. 
Refer¬ 
ence No. 
Increase of 
gaining-rate 
by changing 
the tempera¬ 
ture from Go 
bo 40 degrees. 
Refer¬ 
ence No. 
Increase of 
gaining-ratc 
by changing 
the tempera¬ 
ture from Gu 
to 40 degrees. 
Refer¬ 
ence No. 
Increase of 
enining-rate 
by changing 
the tempera¬ 
ture from GO 
U, 40 degrees. 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
+15-3 
13-1 
8*1 
7-9 
7-8 
• 5-4 
4.4 
3-8 
3-2 
1-9 
1-0 
0-6 
0-3 
+ 0-1 
- 0-8 
10 
H 
1-2 
1-4 
1*5 
1-6 
1-7 
1-9 
1-9 
- 1‘9 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 
38 
39 
! 40 
41 
42 
43 
44 
45 
I 46 
47 
! 48 
| 49 
50 
• 
-1-9 
20 
2-2 
2-3 
2-3 
2-3 
2-4 
2-4 
2-9 
2-9 
2- 9 
3- 0 
30 
31 
31 
3*1 
3-2 
3-2 
3-3 
3-3 
3-3 
3*4 
3-5 
3-7 
-3-7 
51 
52 
53 
54 
55 
56 
57 
58 
59 
GO 
61 
62 
63 
64 
65 
66 
67 
68 
69 
70 
71 
72 
73 
74 
75 
s 
-3-7 
3- 8 
4- 0 
4*1 
4'2 
4-3 
4-3 
4-3 
4*5 
4-5 
4-5 
4*6 
4-6 
4-8 
4-8 
4-9 
4- 9 
5- 0 
5-1 
5*3 
5-3 
5-8 
6*0 
6*1 
- 6*1 
7G 
77 
78 
79 
80 
81 
82 
83 
84 
85 
86 
87 
88 
89 
90 
91 
92 
93 
94 
95 
96 
97 
98 
99 
100 
- 6*2 
6- 3 
C-5 
6-8 
7- 0 
7- 3 
8*1 
8*2 
8*5 
8'6 
8- 7 
8-8 
90 
9'0 
9’1 
9- 6 
10-8 
111 
12-0 
21- 5 
22- 7 
28-1 
45-2 
651 
-72-2 
Average change of daily rate 6*97 seconds. 
