EQUIPMENT, APPARATUS, AM) LH'.KAKV 



13 



Glass. Doublo-tliifk window glass lor sides and ends, and rilibed 

 skylight glass fur bottom for sizes al)ove 20 x 10 x 12 inches. 

 For smaller sizes, waste 10 x 12 in. negatives arc good and 

 cost little or nothing. 



Angle or valley tin, sizes indicated Im-Iow. 



Aiiuarinm cement. 



Solder. 



(ireen or l>lack carriage paint and a little .spar varnish. 



Fig. (i. Making aciuaria 



From left to right, laying the cement; glass set in ..lie. with li.-iit .^reeu twigs 

 to liold it in place; painting frames, and frames ef different sizes, 5x7x4 to 

 24x15x10; cutting the angle tin to measure: solderini; tlie frame hel-l in a 



square fa.stened to table 



Tools. Every laboratory should !•.■ provide.! with a few simple I.k.Is, 

 among which the following will V)e reipiired in making atpiaria : 



Carpenter's sqnare,— to hold the frame perfectly scpiare at each 

 angle while it is being soldered. .V three-way S(inare, ma.le by miiling 

 two 5-inch boards of convenient length at exact right angles aii.l fa.-^ten- 

 ing them to a work table, greatly facilitates getting each angle right at 

 the first trial. 



