364 Astronomical and iSautical Collections. 



and for properly combining them, will generally be somewhat 

 greater than that of the entire computation by the shortest of 

 the methods already enumerated ; and this objection, together 

 with the unwieldly bulk of the volume, will probably be suffi- 

 cient to prevent these tables from ever acquiring any great 

 degree of popularity. 



Example. 

 Taking, as in the last example, d — 59° 26' 34" ; wi = 27" 

 2' 30", s zr 59° 11' 52", and p — 59' 27", we have to proceed 

 thus : 



m 27 [Red. — 36' 58" Log. — 140 

 * 59 J 

 d 59 -j 



wi 27 I — 37 30 — 134 



J 60 J 

 d 59' 



»»28 \ —36 31 —146 



s 59. 

 d 60 



mil \ — 36 37 - 140 



s 59 



Diff. 



for 



1° 



Corr. 



58 43 52 Corr. 41 42 — 286 Par. Log. 4 39 



If there is no mistake in this computation, the example is 

 not very likely to rescue the remaining copies of the tables from 

 their impending fate : for an error of 24' could scarcely have 

 been expected in the coarsest approximation. 



XI. Scales of Reduction. 



Some ingenious attempts have been made to reduce Dr. Shep- 

 herd's tables to the form of scales, partaking more or less of the 



