49 



writer has used the Aneroid as its inventor intended it 

 should be used; and its movements are so far perfect, 

 that they merit the calm and impartial investigation of 

 the true philosopher, whose vocation is to aid the deve- 

 lopment of ingenuity, and not to crush its efforts because 

 they are not perfection. 



The following diagrams are by Mr. Redwood, and the 

 explanation of the Aneroid is nearly the same as that 

 communicated by the same gentleman to the Pharma- 

 ceutical Society. 



Fig. 1. 



^z^&ss&sa&zz^ 



Fig. 1 represents the external appearance of the in- 

 strument. It is four inches and three-quarters in dia- 



Tfc 



