118 ARRANGEMENT OP APPARATUS, ETC. 



vented, by pasting several folds of yellow or black 

 paper, (the latter being preferable) over both interior 

 and exterior. The edges of the sleeves where they 

 join the partition are further secured by tacking 

 thin deal laths round them, which are also covered 

 with black paper. A black cloth curtain with an 

 orifice for the tube of the microscope and fine adjust- 

 ment, should be placed inside the dark room so that 

 it can be let down when the arraugement of the 

 apparatus is complete. 



We suppose the apparatus continuing in the posi- 

 tion assumed during the manipulation necessary for 

 the process last described. 



The stand is placed in the horizontal position by 

 the removal of the camera legs ; all the instruments 

 are detached from it and carefully put aside; the 

 side boards are changed from their original position 

 and shifted two bolts lower down, or till flush with 

 the extremity of division No. 3, and firmly screwed 

 on. This keeps the two last divisions perfectly rigid, 

 and enables us to fold division No. 1 under them ; 

 where it also is firmly secured by one or more of the 

 binding screws, running in the slits with which the 

 Ci ntres of Nos. 1 and 3 are furnished. 



Thus folded up and tightly secured, the stand is 

 placed, with the platform for the microscope in front, 

 on the stand forming the floor of the recess. 



The ruby lamp is now lit in the dark room, and 

 all necessaries (such as developing solutions, dry 

 plates, dishes, etc.) examined and put in their pro- 

 per places. 



