314 



REPORTS ON THE STATE OF SCIENCE. 



Several opaque objects, such as a watch face, pencil diagrams on a porcelain 

 slate, pieces of polished marble, and small fossils, were shown satisfactorily 

 on the screen. It is hoped that the use of a water-tank with glass sides may 

 reduce the heat sufficiently to enable natural history specimens to be safely 

 shown. 



The accompanying sketch shows diagrammatically the general arrangement of 

 the apparatus in side elevation. 



A. Four-arc lamp in profile; b. cooling tank; c, object on adjustable block; 

 D concave white screens; e, rapid portrait lens; h, plane mirror; k, path of 

 rays to 6creen. 



The thanks of the meeting for the Chairman's valuable address and demonstra- 

 tion were proposed by Professor P. F. Kendall. 



Mr. A. Archibald (Tunbridge Wells Natural History and Philosophical 

 Society), in seconding the vote of thanks, said that he would like to mention that 

 a simple form of instrument upon the principle of the aphengescope will be 

 found of great value in the class-room, but to place the image in its correct 

 position the lantern and reflector attached should be placed at the back of a glass 

 screen. The "lass should be as thin as possible, having a frosted or opaque surface 

 to the audience. Certain mechanical arrangements of shape and reflector can be 

 used according as the flat or raised surface of objects is required for projection. 

 The cost of such an instrument would be very small apart from the ordinary 

 lantern to which it is fixed. He has found the instrument most useful in the 

 field of numismatics and geology. 



Systematic Recording of Captures, 



Mr. F. Balfour Browne (Belfast Naturalises' Field Club) opened a discussion 

 on the following motion : ' That a Committee of Biologists be formed to recom- 

 mend the adoption of a Definite System on which collectors should record their 

 captures.' He said that his aim was to make the work of the collector 

 more capable of assimilation by those who study distribution in the 

 British Islands. He pointed out that in a great number of cases the collector 

 publishes his list of captures, only vaguely indicating the limits of the district 

 he has worked, such titles as ' Butterflies from the neighbourhood of ..." or 

 'Beetles in the district surrounding . . .' being common. 



If all naturalists would adopt a uniform system of recording the results of their 

 collecting a great deal of trouble would be saved to the student of distribution. 



