1820.] the Rev. Dr. Hales. 171 



He was not more ambitious of literary honours. And in 1753 

 he was named a foreign associate of the French Academy of 

 Sciences, solely on account of his reputation, without any solici- 

 tation v>'hatever on his part. His manners were particularly- 

 amiable ; and in the cast of his character he is said to have had 

 a very considerable resemblance to the celebrated Boyle. The 

 sole object of all his labours was public utility; and he seems to 

 have had no otlier ambition than that of discharging: his duties 

 to his country and to mankind in general. A single example 

 will be a sufficient specimen of the gentleness and humanity of 

 his disposition. His haemastatics were not carried nearly so far 

 as his vegetable statics. He assigned the reason of this in a 

 letter which he v/rote to M. Duhamel. The tortures, to which he 

 was under the necessity of subjecting the inferior animals, preyed 

 upon his mind so much, that he durst not venture to proceed 

 with his experiments, but found it necessary to drop the subject 

 altogether. 



Dr. Hales was married, and always lived with his wife in the 

 most perfect harmony, but it does not appear that he left any 

 children. 



Article II. 



Description of a Barometer for measuring Heights. 

 By Mr. James Allan. 



(To Dr. Thomson.) 



SIR, Erskine, Jan. 26, 1 SiO. 



The following is a description of a convenient barometer for 

 measuring heights, which I send you for insertion in the Annals 

 of Philosopliif. 



This barometer is of the recurve kind. The turned up partis 

 a piece of wide tube, in v/hich an iron float is to be put to swim 

 on the top of the mercury to prevent its convexity. The propor- 

 tion of tliis to the long tube must be accurately ascertained. 

 We shall consider it to be as 12 to 1. A scale of inches, as in 

 other mountain barometers, is to be attached to the top of the 

 tube on the one side, bv which to mark the positions of the 

 mer(tury in the column of suspension. Then from the proportion 

 of the tubes being to one another as 12 to 1, for every 12 parts 

 the mercury falls on this scale, it will rise one part in the turned 

 up tube ; so that the column of suspension will be shortened 13 

 parts. Hence, when the quantity of fall on the scale is 

 correctly found, it is only necessary to add one-twelfth part of 

 itself to it to know how much tlie column of suspension is 

 shortened. 



This, however, may be found more easily by means of a scale, 



