8& Koyal Society of London, 



tors, tranfit inftruments. Sec. by Ramfden and other emi- 

 nent Englifli artids. But though artronomy has been fo 

 much improved in this country, we were far behind fome 

 of our neighbours on the continent, in regard to good works 

 on the fiibje6t. We do not here mean to throw out any 

 refleftions againft thofe authors who have written on aftro- 

 nomy, many of whom are jultly entitled to praife. But 

 we are of opinion that none of thefe works, the fyftem of 

 profeflbr Vince excepted, is fuited to the prefcnt improved 

 ilate of the fcience ; for woiks of aftrcnomv? from the na- 

 ture of the fubjetl on which they treat, the necefiity of fre- 

 quently correcting the tables, and other circumftuuce^, muft 

 have a very limited period of utility. As profelfor Vmce's 

 work is too bulky and expenfive for the great rnafs of the 

 public, it gives us pleafure to find that a gentleman fo well 

 qualified for the taflc as Mr. Gregory feenis to be, has turned 

 his attention to this deficiency, and fupplied the public with 

 a comprehenfive, clear, and well arranged elementary trea- 

 tife on this noble and ufeful fcience. We have no hclitation 

 in faying, that we confider it as the bed: prailical work on 

 the fubjeil publilhed fince the time of Leadbetter. Vhe 

 author's rules are fimple and eafy : and the whole rendered 

 fo familiar, by a variety of examples, that any perfon ini- 

 tiated in the principles of the mathematical fciences muft 

 readily comprehend them. It will be of ^reat utility to 

 young perfons in particular, who are ftudying aftronomy; 

 and thofe who have made conilderable proficiency v/iU find 

 It exceedingly convenient to refer to. The author has omit- 

 ted none of the modern difcoveries ; and the tables he has 

 given at the end are taken from the befl fources, and improved 

 by the latell corre£lions. 



D 



XVIII. Proceedings of ]Learned Scc'wtUs, 



ROYAL SOCIETY OF LONDON. 



R. GIBBES, in a paper on galvanifm, read before the 

 Society on the 2i(l of January, afliunes an opinion contrary 

 to that of Dr. Wollafton, reipefting the origin of eleiSlricity 

 in chemical changes^ and maintains, that the ele6lrical 

 changes are to be confidered as preceding and favouring the 

 chemical. He imagines that the fimple contact of various 

 fubftances produces changes of ele6liical equilibrium, and 

 that the a6lion of acids is effetSlual in promoting thefe 

 changes by bringing their furfaces into contact. Dr. Gibbes 



pbfervcs 



