Royal Microscopical Sociekj. 



91 



makers, and it cannot be said that the important principle involved 

 in their construction is now neglected in this country. 



Three new binoculars have been produced : one by Mr. Holmes, 

 ingeniously formed of split lenses ; one for high or low powers by 

 Mr. Stephenson, on a plan quite different from that of Mr. Wenham ; 

 and one by Mr. Ahrens, for high powers, constructed uj^on a new 

 principle with the aid of double-refracting spar. 



For details of the optical construction of Mr. Stephenson's 

 instrument, we must refer to his paper already published in the 

 Journal. His plan gives, for the first time in a binocular, erect 

 instead of inverted vision, which is often a matter of great con- 

 venience. Its action with high powers is really stereoscopic. 



Dr. Carpenter contributed the comparative results, as regards 

 steadiness at sea, of instruments of moderate weight and size on the 

 Eoss and Jackson models ; and several minor matters have formed 

 the subjects of communication. 



The mere enumeration of the topics that have been brought 

 before the Society during the past year will suffice to show the value 

 of its operations ; and in addition to the publication of its papers 

 and ' Transactions ' in the Monthly Journal, Dr. Lawson has ably 

 carried out the wishes of the Council in connecting your Society 

 with that publication, by bringing to a fo'cus a great mass of micro- 

 scopical research made by various English and foreign observers, 

 and which were virtually inaccessible to ordinary students in their 

 scattered state. 



Conspectus of the Present State of the Society. 



Books Purchased during the Year. 



' The Annals of Natural History,' 44 vols., or nearly all the first 

 three series of the work, making it quite complete to the present 

 time. 

 ' Straus Durckheim Anatomic Comparee.' 

 * The Quarterly Journal of ]\Iicroscopical Science,' vol. 18. 



The numerous valuable donations have been periodically an- 

 nounced in the ' Monthly Microscopical Journal.' 



H 2 



