3iS 
A VOYAGE TO 
1779. where the rate was laft taken, to the place whofe longitude 
is laft determined. The thirteenth and fourteenth contain 
the ftate of the air at the time of each obfervation. 
As perfons, unaccuftomed to calculations of this fort, 
may find fome difficulty in comprehending the nature of 
the table, the two following inftances will more clearly ex¬ 
plain it. 
Thus, on the 24th October, 1776 (firft column), at the 
Cape of Good Hope (fecond column), we found the daily 
error in the rate of its going, to be 2",26 (third column. 
The longitude of that place, calculated on a fuppofition that 
the rate of the time-keeper had continued the fame from 
the time of our leaving Greenwich, that is, had a regular 
daily error of i // ,2i, is found to be 18 0 16' 30" Eaft (fourth 
column). And as its rate at Greenwich is, in this inftance, 
its lateft rate, the longitude thus found is the fame (fifth 
column). The true longitude of the place is 18 0 23' 15" 
(fixth column). From whence it appears, that in our run 
from Greenwich to the Cape, the watch would have led us 
into an error only of 3' 15" (feventh column), or three 
miles one quarter; or had varied 13" of time (eighth co¬ 
lumn), in four months twenty-three days (ninth column), 
the period between our leaving Greenwich and our arrival 
at the Cape. As the Greenwich is the lateft error, the 
tenth, eleventh, and twelfth columns will be the fame with 
the feventh and ninth. 
But, on the 22d of February, 1777 (firft column), at 
Queen Charlotte’s Sound, New Zealand (fecond column), 
the daily error of its rate was found to be 2",91 (third co¬ 
lumn). The longitude of this place, according to the Green¬ 
wich rate, is 175 0 25' (fourth column). But having found, 
at the Cape, that it had altered its rate from a daily error of 
I",*!, 
