June, 1891.] 



THE 



SCIENTIFIC TEAN8ACTI0NS 



or THE 



ROYAL DUBLIN SOCIETY. 



VOLUME IV. (SERIES II.) 



YIII. 



THE CONSTETJCTION OF TELESCOPIC OBJECT-GLASSES FOE THE INTEE- 

 NATIONAL PHOTOGEAPHIC SUEVET OF THE HEAVENS. By SIE 

 HOWAED GEUBB, M.A.I., F.E.S., Hon. Sec, Eoyal Dublin Society. 



DUBLIN: 



PUBLISHED BY THE EOYAL DUBLIN SOCIETY. 



LONDON: WILLIAMS AND NORGATE. 



PRINTED AT THE UNIVERSITY PRESS, BY PONSONBY AND WELDRICK, 



PEINTEES TO THE SOCIETY. 



1891. 



Price One Shilling. 



