Knowledge. 



With which is incorporated Kard\vicl;c's Science Gossip, and the Illustrated Scientific Nc's. 



A Monthly Record of Science. 



Conducted by Wilfred Mark Webb, F.L.S., and E. S. Grew, M,A. 



FEBRUARY, 1911. 



APPARATUS FOR PHOTOGRAPHING NATURAL 



HISTORY OBJECTS, 



Bv \\". FOTHERIXCHAM. 



Collect, e.xamine and record, is probabh- a good 

 sumniar\' of the work of the average Nature student. 

 He has not gone far in his work when he innds that 

 to properly examine all he collects lie requires a 

 microscope, and that to record his finds in the easiest 

 and most truthful \\ay, he must 

 have a camera. Now the enthusiast 

 will soon find himself in difficulties 

 about apparatus, especially apparatus 

 for recording his facts, either for 

 future comparison or for the benefit 

 of others. \\'hat ought to be a 

 pleasure, the making of an interest- 

 ing, perhaps [)rett\', picture of his 

 facts, is, owing to tault\- apparatus, 

 a disagreeable task, costly in time 

 and uncertain in results. So for 

 ever\- ten who are skilled in the 

 first two parts of the work there 

 is probabh- not one in the third. 

 To carry out this programme let 

 us see what is needed. Supposing 

 the collecting and examining be 

 "taken as read." he requires: — 



(1) A Field Camera. If this is of the -hand 

 or stand" type, it will "cover a multitude" of 

 things. 



With it he inav. with some circumlocution, 

 even take at home, with pains, indifferently good 



Figlike 1. ' 

 The Camera used for enlarging or reducing. 



With improvised condenser and jet on optical bench. Also a snpplementary board, on which olijects ma>- be 

 pinned out when the apparatus is used as ordinary or copying camera. 



.^ 15x12 Photoinicrographic Camera. 



With woihIcii optical bench, Watson "Van Heurck" microscope, Nelson Condenser, and acetylene jet on 

 sliding wooden feel, permitting right angle centring adjustments. 



pictures of " birds, beasts and 

 reptiles." 



Ultimately he will probab]\ get 

 a bigger camer:i on legs, that beha\-e 

 themselves better on a floor th;ui do 

 those of the ordinary field tripod. 



Even then he will be annoyed 

 to find that he cannot take a picture 

 of many things, in spite of much 

 }.)inning-out and arranging on board 

 or wall, and that such things as 

 eggs have an ugly shadow round 

 them, while fragile dissections are 

 out of the question, as is an\- pre- 

 paration floating in fluid. He will 

 probably long for a vertical arrange- 

 ment that will enable objects to be 



41 



