45$ 



Analyses of Books. 



[June, 



Mrignetical Observations conthined. 



Article X. 



Analyses op Books. 



A Treatise on New Philosophical Instrumenls for various Purposes 

 in the Arts and Sciences, luith Experiments on Light and Colours. 

 "By David Brewster, LL. D. F. R. S. and A, Edin. 



This treatise is divided into five books. 



Book 1. treats of new micrometers for measuring small angles 

 and distances in the heavens, and of the fibres most proper for these 

 instiunieiits. 



• Book Jl. treats of instruments for measuring angles when the eye 

 is not at tlieir vertex. 



Book 111. treats of instruments for measuring distances. 



Book IV. contains the description of instruments for viewing 

 objects under water ; for measuring the refractive and dispersive 

 powers of bodies. It comprehends also a very extensive series of 

 experiments on the refriictive and dispei-sive powers of various solid 

 and fluid substances, .md an account of new properties communi- 

 cated to light by transmission through diaphanous media, and by 

 reflection from the polished sui faces of opake and transparent 

 ■bodies. 



Book V. treats of new telescopes and microscopes, and contains 

 a series of experiments on the action of refracting media upon the 

 ditferently coloured rays. 



