Short, but plain and easy, directions for the use of Hadley's quadrant. In which care is taken not to encumber it with more than is necessary, or needless encomiums, but to render it useful to the learner; it being now so well known to the world as not to want an advocate in its praise. To which is added, a description of the vernier scale, commonly call'd nonius's division.

Date:

[1755?]