388 ANNUAL OF SCIENTIFIC DISCOVERT. 



and thence to lead to the conclusion that all the other planets were uninhab- 

 ited also. The point was, that "observations having been made on the moon 

 abundantly sufficient to detect the change caused by the growth of such 

 cities as Manchester and Birmingham, no such changes having been perceived, 

 the theory of non-habitation may be indulged in." But after having indicated 

 the sort of appearance that those collections of human habitations would 

 make when transferred to the moon, Professor Smyth proceeded to show that 

 the registered and published observations of the moon are by no means suf- 

 ficiently accurate to be used to test question : and that they do show changes, 

 and often to a far greater amount than the mere building of a lunar Manches- 

 ter would occasion, but such changes bear the impress of error of observation. 

 More powerfully still was this brought out, on comparing even the best of 

 the published documents with some manuscript drawings of the Mare Crisium 

 in the moon, recently made at the Edinburgh Observatory, and the author 

 hoped that this statement of the imperfection of existing maps would lead to 

 observers generally applying themselves to improve this important and inter- 

 esting field of astronomy. Professor C. Piazzi Smyth. 





