GOING OP THE CHRONOMETERS. 
XI 
Their actual differences, ascertained by comparison at the observatory 
at Calton Hill, were, 
h. m. s. 
228 
slow 3 
04 
05.03 
253 
— 2 
29 
40.48 
254 
— 0 
21 
22.68 
259 
— 0 
44 
35.35 
6 
39 
43.54 
The difference being divided by 4, (the number of the chronometers) gives 
1\815 fast, as the error of the Greenwich time shewn by the chrono- 
meters at the end of 104 days, on being allowed the average daily rates 
at which they had gone for the three months preceding the period. 
The longitude of the western parts of Melville Island, and of a con- 
siderable portion of the western coast of Baffin’s Bay, and Davis’ Strait, 
which were surveyed in the season of 1820, have been accordingly determined 
by the mean of these four chronometers, using the above-mentioned rates. 
Table VI. exhibits the daily rate of these chronometers, and of No. 2109, 
each successively on the other four, averaged in weeks, from the com- 
mencement to the close of the navigation of 1820. 
The ships having arrived at Deptford, the chronometers were delivered 
on the 1st of December, to steady persons sent by their makers to receive 
them. 
Table VII. contains a statement of their daily going on time since their 
return to London ; the materials of this statement have been furnished by 
the makers, who had not received any intimation of the previous rates. 
Admirably as these chronometers have fulfilled the purposes for which 
they were employed, it is an additional satisfaction to find, that, notwith- 
standing the change of circumstances attendant on their disembarkation, 
and replacement in their makers’ care, they are still maintaining almost 
without exception, their Melville Island rates. 
Nos. 369 and 404, which had stopped in the winter at Melville Island, 
without any apparent cause, and had been reserved for Mr. Arnold’s eX- 
fa 2 
