Celestial and Terrestrial Globes. 193

By this method of calculation, we avoidany mistake that might happen with respectto the intercalary day; because we find theautumnal equinox first, and thence the vernalequinox, which always falls after the inter-calary day, and also because tropical time hasno bissextile years.

To reduce hours, minutes, andseconds of time, into degrees,minutes, and seconds of the e-quator.

275. Divide the seconds of time by 4,the quotient is minutes, and remainder somany times 15 seconds.

Divide the minutes by 4, the quotient is,degrees, and remainder so many times 15minutes.

Multiply the hours by 15, the productis degrees.

O

Example.