Se | Pee ee 
L288) I 
the variation in 1750, and not in’ 1751, was 19 degrees, and that 
he had no idea of its being more.in 1751 or 1752 than in the year 
1750, agreeable toa former remark. This miftake of Mr. Gibfon 
accounts for the difference in the fecond example of the general 
operation, and the firft and fecond of the intermediate dates. For 
inftance, if it be allowed that in the year 1750 the variation was 
19 degrees wefterly, let the fecond example of the general operation 
be repeated thus: From 1750 take 1657, the remainder is 93; 
divide 19 degrees, reduced to minutes, viz. 1140 by 93, the 
quotient is 12 minutes 16 feconds, nearly, inftead of 12 minutes 
8 feconds, as is there ftated. 'Again, in the firft example of 
the intermediate dates, from 1750 take 1745, the remain- 
der is five years, and from 19 degrees take 18, the remain- 
der is one degree, equal to 60 minutes, which divided by 5 
quotes 12 minutes. [Here again I cannot help remarking that 
even the deficiency in this inftance may be the confequence of 
a want of precifion in the interval of time as well as the quantity 
of the variation ; five months would have made the ratio complete, 
and as it certainly was Mr. Kendrick’s cuftom (as well as Mr. 
Gibfon’s). to write the fame variation feveral years, no doubt 
he might have written the fame-in 1744. This will be worth 
trying bythe ratio ; \that is, letit be required by the annual rate 
of 12-minutes 20 feconds to find when the variation was 18 
degrees wefterly.: I fhall poftpone the operation till the interme- 
' diate dates are finifhed.]. In the fecond example, fay, from 
1772, take 1750, the remainder is 22 years, and from 23 
degrees 30 minutes take 1g degrees, the remainder is 4 degrees 
Q:2 30 
