\ 
100 Chronometers. [Sept I, 
acertain regular rate; and whéther it in London, were sent to the Observa- 
be a little too fast, or alittle too slow, tory at Greenwich, on trial, and were 
is immaterial, provided it be according kept one year, excepting that fori about 
to a known rate, so that by observing two months some of them) were sent 
the exact second’ on'the chronometer, out for observation carried on at) Fal- 
the precise time may be known. This mouth: Their rate of going, was ob- 
is now brought to such a degree of per- served with rigorous astronomical accu- 
fection, that a difference of a second not racy every day. To exhibit to the reader 
merely in a day, but in'a month, is an the high perfection to which those in- 
object of consideration. With instru- struments have been brought, there is 
ments of such accuracy, the longitude here subjoined’ a copy of the official 
of any place may be determined with the account published of the daily rate of - 
greatest exactness, as an error of four the chronometer made by Mr. Murray, 
seconds in time will give an error of of Cornhill, which gained the first pre- 
only 1’ of longitude, which at the equa- mium price of 300/., which is now sent 
tor is little more than an English mile, out with Captain Parry. It is the best 
and gradually diminishes on approach- instrument ever known ; and the great- 
ing either pole. est variation in its mean daily rate of 
In the beginning of 1823, thirty-six going did not exceed one second and 
chronometers, made by the best artists eleven hundredth parts of a second. 
TABLE. 
ss a) akg: pli (8 : 5 . 
Be gee ae eee ae, on fe tembet si q vember cemiber Ao 
Qs = 1823, 1893. 1893, 
| — | +1’.1} +0%3] +0%.4) +0%.5 +1’.3| +071] +2”.0) +1’.1] +0”.8 
2.{ — |+1.9) +1.1] 40.4) +1 .4 +0.7) +1.1] +1.3] +1.9 8 
3.) — | +1.1}+0.4!40.9] 40.7 +1.0} +1.0] +0.9| 41.6 3 
4.{ +1’.1 | +0 .2| +0 .4}+0.6) 40.7 +2.4)+0.7| +1.1/ 40.7 8 
5.| 40.8} +0.8] +0.3/+0.9| +0.4 41 4) 47 4) 49"5 | 40.7 0 
6.| +0 .2| +0 .5! +0.5] +0.6] +0.8 +1.3}) 41.4) 41.2) 40.7 0 
7.{ 0.0] +0.6} +2.4] +0.3] +0.8 +2 .2} +1.8)+4+0.5) +013 5 
8./—0.4) +0.8} +1.7| +1 .2] 40.8 +0.9| +1 .5) 40.5) 40.5 0 
9.|+0.4} +0.6| +0.5] +1 .2) 40.6 +1 .5) 41.3) 40.6) +40 .3 0 
10.}+0.3) +1.1} +1.0| +0.4) +1.9 +1 .2| 41.2} +07) 40.6 8 
11.}—0.1{ +0.7| +0.6] +1 .0/ 40.1 +1 .3| +1 .2} 40.8) 40.8 0 
12.|+1.3| +0 .6) +0.6| +1 .0] 40.9] | +1 .8) +0..8),4+1.5) +0 .8 5 
13.{4+0.1] +0 .3| +0.9]+1.1!}41.2/4] 2 +1.9| 40.3) 40.4) 40.01 a 
14./40.6] +0 .3; +0.7| 41.5] +1.2)2) 3 +1.8} +0 .0/.4+1.2) —0.8 6 
15.|+1.9] +0.5) +0.7/ 40.7) 40.6)8| 2 | 41.4) 40.0] 41.2) —1.6 0 
16. |—0 .2} +0.5} +0.2}+0.7/40.8/)2| 3 |42.0/ 41.0] 49.2) 0.8 0 
17. |—0 .2| +0 .2)40.7|+4+0.4)40.7/2| ™ 140.9} 41.1] +1.2)—0'6 1 
18.}40.3/ +2.3) 40.6] 41.4) 40.5/4} 2 41.0} +1.0] +1 .9) —1.0 1 
19.|+0.2} +0.7) +0.5/+0.9| 40.7 +1 .8) +0.5| 40.5) —1"] 6 
20./—1.1) +0.7| +0.8}+0.6| 40.6 +1.9} 41.2} —0.1) —0.3 3 
21.;—0.6) +0.7) +1.1/41.6| 40.7 41.9] 40.7] 910) 40.6 8 
22. 0.3} +0.2) +0.8| 41.3] +1.0 +0 .6) 41.2} 9.0) 47.4 6 
23./41.4] +1.0) +0.5/ 41.3) 40.1 2.0) +1.1) +0 68) +7.1 6 
24./+1.4| +0.7) +0.6) +0 .9| —0.2 1.0} 41.1) +0.6) 41.5 5 
25.|+0.6] +9.9} 40.9) 41.0 +1’.7} 42.1) 40.9} 41.6} 41.1 1 
26./40.2] +9 .6) 40.8} 41.3 : +0 .8) 41.1) 41.2) +1.7|.41.2 3 
27./40.3| 49.6) 40.6) 41.3] 3 41.1) 4) 2) 47 21 47 O) 7 8 2 
28. /—90 .4| +9.5/ 40.9] 41.4) 28 FTO, 4) 3) tT tt 2 eS 9 
29./40.1/ 9.0) 41.1} 41.2] 38 +1.0} 42.2] 41.2] 41.2] 40.8 
30.} 41.0} +1.0/ 40.6] 41.1) & +0.8| 40.8] 41.5] 41 .11'4073 
31.} 41.1 +0.5 2 42 .2 Sat pne sions 
& +0".38)+ 0”.72)+-0".75 |+-0".95|-+0".73| - |4-1".07|4 1”.49]+ 1”.01 Aa iigd we 
Greatest | Gamera acl. ly:atniy seta pile ands’ v\cfeta Mo tee. Gbiciopsneaesh raat! 1.49 
Least Gaining ........ misikisiele Bis ,p0) 46 Sorbie Spee, 0's) slot as iwiers Ohie's sf OG 
Variations, ic,cers oie cmcwinels filer il 
