The Observatory at St. Martin. 357 



A Microscope and apparatus for the examination of snow crys- 

 tals and also obtaining copies by the chromotype process, is also 

 provided. 



The Electrical Apparatus. — This consists of three parts: a hoist- 

 ing, a collecting and a receiving apparatus. 



The hoisting apparatus consists of a pole or mast 80 feet. 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 two-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, extending from the top to the bottom of the pole, 

 and forms a sort of vertical railway; these pieces are also grooved 

 or rebated to receive a slide, which runs in these grooves and carries 

 the receiving apparatus. 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. It has also been used for the 

 purpose of placing the ozonometer 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 four stays. These cross timbers are 

 loaded with stones, and are thus rendered sufficiently 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 top of a copper rod | inch thick 

 and 4 feet long : the bottom of the lantern having a piece of copper 

 tube 1 fixed to it, a very little larger than the rod, and is thus easily 

 removed and replaced. To the lower end of the copper rod is sol- 

 dered an inverted copper funnel, a parapluie, for protecting the 

 glass insulating pillar upon which it is fixed by means of a short 

 tube firmly soldered to the underside of the parapluie. This glass 

 pillar passes into and is fixed firmly in a wooden box, and is freely 

 exposed to the heat of a second lamp, which is placed in this box. 

 It is trimmed at the same time as that in the collecting lantern, 

 and keeps warm and dry the glass pillar, by that means securing 

 a more perfect insulation. From this upright rod and collecting 

 apparatus descends a thick copper wire which serves to convey 



