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.

Biblio’s Book Conditions

• As New
  The book is pristine and free of any defects, in the same condition as when it was first newly published.
• Fine (F)
  A book in fine condition exhibits no flaws. A fine condition book closely approaches As New condition, but may lack the crispness of an uncirculated, unopened volume.
• Near Fine (NrFine or NF)
  Almost perfect, but not quite fine. Any defect outside of shelf-wear should be noted.
• Very Good (VG)
  A used book that does show some small signs of wear - but no tears - on either binding or paper. Very good items should not have writing or highlighting.
• Good (G or Gd.)
  The average used and worn book that has all pages or leaves present. ‘Good’ items often include writing and highlighting and may be ex-library. Any defects should be noted. The oft-repeated aphorism in the book collecting world is “good isn’t very good.”
• Fair
  It is best to assume that a “fair” book is in rough shape but still readable.
• Poor (P)
  A book with significant wear and faults. A poor condition book can still make a good reading copy but is generally not collectible unless the item is very scarce. Any missing pages must be specifically noted.