276 Mr. Ellis on the Corrections for Latitude [May 18, 



rection for the variation of gravity on the vertical. They have the further 

 advantage of being applicable to both English and continental measures. 

 The unavoidable uncertainties of the theory make it useless to consider more 

 minute quantities than a foot, or the hundredth of a metre or of a toise. 

 Hence only five-figure logarithms are required. The following examples 

 will show the use of these Tables. 



Ex. 1. (Feet and Fahrenheit.) Part of Glaisher's Balloon Ascent, 

 5th Sept. 1862. (Report of British Association, 1862.) 



B' 20717 A 32-1 H 9835 



V 17-931 a 25-5 L 53 



836-0 



T 893-6 



logB' 1-31633 W. T. G 3754 



log 6' 1-25360 H 9885 



v for 14000 9 



W -06273 V for 10000 -5 



logW 879748 h 13643 



logT 2-95114 

 lat. 53, log G 1-82583 



log (W. T. G) 3-57445 



Ex. 2. (Metres and Centigrade.) Mont Blanc, taking St. Bernard 

 the lower station. (Ann. Meteorol. de France, 1852.) 



B' -56803 A' 7-6 H t 2463 



b' -42429 a' -9-1 L 46 



500-0 



T' 498-5 



log B' 9-75437 W. T'. G 2 2322 



log b' 9-62766 Hj 2463 



v l for 4800 3-6 



W -12671 V 2 for 2400 -0'9 



logW 9-10281 A, 4787*7 



log T' 2-69767 

 lat. 46 1 1-82610 

 log G 2 } 9-73928 



log (W. T'. G a ) 3-36586 



Ex. 3. (Toises and Centigrade.) Monte Gregorio (cited by Bessel from 

 D'Aubuissori's Geognosie, i. 481). 



