The President's Address. By Prof. P. Martin Duncan. 185 



and came to England, entering the house of the late Andrew Eoss, 

 the founder of the well-known optician's business bearing his 

 name. Mr. Dallmeyer's attention was at first devoted principally 

 to the construction of astronomical telescopes, for which, in 

 conjunction with Mr. Koss, he computed a large number of 

 formulae.. At his death, Mr. Koss bequeathed to Mr. Dallmeyer 

 the bulk of his optical appliances for the manufacture of telescopes. 

 About this date (1855) photography began to be popularized by 

 the general adoption of the collodion process, Mr. Dallmeyer 

 quickly discovered that the photographic lenses then in use stood 

 in great need of improvement in every direction. In rapid suc- 

 cession he produced lenses for landscape and portrait photography, 

 and it is greatly owing to his efforts that Enghsh lenses now rank 

 second to none. He was specially commissioned to provide several 

 of the telescopes and photographic appliances used by the different 

 Government expeditions for the observation of the recent transit 

 of Venus, and his telescope object-glasses are in high repute among 

 the leading astronomers. Mr. Dallmeyer died at tbe age of 53. 



One more duty falls upon me, and it is a very pleasurable one. 

 I have to thank the Fellows of the Society for the consideration 

 they have shown me during my three years of ofiSce, and for the 

 manner in which they have borne with my shortcomings. In 

 taking leave of you as your retiring President I do most sincerely 

 congratulate you on the accession of Mr. Dallinger to the presi- 

 dential chair, a position for which his great scientific reputation so 

 thoroughly recommends him. 



Ser. 2.— Vol. IV. 



