Sessions Clocks

Select mechanical exercises, shewing how to construct different clocks, orreries, and sun-dials, on plain and easy principles : with several miscellaneous articles, and new tables, I. for expeditiously computing the time of any new or full moon within the limits of 6000 years before and after the 18th century II. for graduating and examining the usual lines on the sector, plain scale, and gunter : to which is prefixed, a short account of the life of the author