SEXAGESI31AL, a name given to the system of reckoning in which each unit is the sixtieth part of the preceding, to which, in our day, we are only accustomed by the method of measuring angles and time. The Greeks, and Ptolemy in particular, brought this method into use in astronomical matters, and their successors seem to have attempted to make it a general mode of reckoning. There exist treatises of arithmetic fashioned on this system ; one, for instance by BARLAAM. [Bloc. Div.] In the sexagesimal arithmetic, 17 26' 48" 53"' 9w stands for 17 units + 26-sixtieths of a unit, or 26 minutes or serupula prima [Scacm.E] + 48-rixtieths of a miilute, or 48 seconds or scrupula setunda + 53-sixtieths of a second, or 53 thirds or scrupula tertia + 9-sixtieths of a third, or 9 fourths or scrupula quartet.
Addition and subtraction are easy enough in this system ; multipli cation, division, and the extraction of roots are more complicated. If we had, for example, to multiply 7 26' 43" 51'" by 11 47' 18" 56"', each term of one factor must be multiplied by every term of the other, and the denomination of each product must be as high as those of both factors put together. Thus when we come to 43" x 56", the result
must be in fifths (2 + 3=5); and 43x 56 being 2408, we have 2408', or 401" 8". This process was aided by a large sexagesimal multiplication table, which may be seen in Delambre, Astronomic Ancienne,' vol. There is also a large sexcentenary table, constructed by John Bernoulli (111.), and published (or republished) by the British Board of Longi tude. There is little need to give any further account of sexagesimal processes.
(the sextant), a constellation which Hevelius had the singular bad taste to place on the back of the Hydra and at the feet of the Lion. It comes directly between the bright stars a Leonia (Regulua), and a (or Cor) Hydro. There are no stars of conspicuous magnitude in this constellation.