METEOROLOGY. 317 



The evaporator exposes a surface of 100 inches ; the amount of 

 evaporation from the surface of ice is measured during the winter 

 months. 



The ozonometers are Schonbien's & Moffat's, one is raised to the 

 altitude of 80 feet. 



A microscope and apparatus for the examination of snow crystals, 

 and obtaining copies by the chromotype process. 



The electrical apparatus. — This consists of three parts : a hoisting 

 a collecting and a receiving apparatus. 



The hoisting apparatus consists of a pole or mast 80 feet high. It 

 is in two pieces, but is spliced and bound with hoop iron, and squared 

 or dressed on one face for about six inches. It is dressed in a straight 

 line to receive cross pieces of 2-inch plank, 8 inches wide and 12 

 inches long, which are firmly nailed to the mast or pole about 

 three feet apart ; this serves as a ladder to climb the pole in case of 

 necessity. Each of these cross pieces is rebated to receive pieces of 

 inch board, 4 inches wide, and placed edgeways in the rebate, extend- 

 ing from the top to the bottom of the pole, and forms a sort of verti- 

 cal railway ; these pieces are also grooved or rebated to receive a 

 slide, which runs in these grooves and carries the receiving appa- 

 ratus. From the top of the sliding piece passes a rope over a pulley 

 fixed at the top of the mast, and from it to a roller and windlass, by 

 which means the collecting lantern is raised or lowered for trimming 

 the lamps. I have also used it for the purpose of placing an ozonom- 

 eter at that height (80 feet.) The lower part of the mast or pole is 

 fixed into a cross piece of heavy timber, and is supported by 4 stays. 

 These cross timbers are loaded with stones, and are thus rendered 

 sufiiciently firm. 



The collecting apparatus consists of a copper lantern 3 inches in 

 diameter, 5 inches high. — (See top of mast G-, fig. 1. The bottom is 

 moveable and the lamp is placed in it by the means of a small copper 

 pin passing in a slit, which is a very easy method of fixing it. This 

 lantern is placed on the top of a copper rod of f inch thick and 4 feet 

 long ; the bottom of the lantern having a piece of copper tube fixed to 

 it, a very little larger than the rod, and is thus easily removed and re- 

 placed. To the lower end of the copper rod is soldered an inverted 

 copper funnel, a j^a^'ap^^^i^ , for protecting the glass insulating pillar 

 upon which it is fixed by means of a short tube firmly soldered to the 

 underside of i\\e parapluie . This ghiss pillar passes into and is fixed 

 firmly into a wooden box, and is freely exposed to the heat of a second 

 lamp, which is placed in this box and is trimmed at the same time as 

 that in the collecting lantern, and keeps warm and dry the glass 

 pillar, and by that means securing a more perfect insulation. From 

 this upright rod and collecting apparatus descends a thick copper 

 wire, which serves to convey the accumulated electricity to the receiver 

 which is placed in the observatory. 



The receiver consists of a cross of brass tubes (gas tubes), each 

 about 2 feet long, and is screwed into a large tube which fits upon a 

 glass cone, which is hollow, forming a system of hollow pipes for the 

 passage of the heat internally, and keep up a certain amount of dry- 

 ness and consequent insulation. The glass cone is fixed upon a table 



