ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



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preferred, on an ordinary triangle camera-stand. The funnel a should 

 have a shorter stem than as figured, which was drawn to avoid confu- 

 sion in the figure ; and to still further simplify it and get rid of some 

 of the weight, it can be made to fit the neck of the tube h, as a 

 stopper fits a bottle. This is believed to be the preferable way, 

 whether the funnel be of glass or sheet-metal, and in this case the 

 platinum wire support c, can be fixed by a small adjustable clamp- 

 ing ring, to the tube which passes through the brass cap at the 

 opposite end of h. The wings can also be made to fix on this cap, and 



Fig. 22. 



Fig. 23. 



thus still further reduce the weight by 

 getting rid of the split ring, to which 

 they were fastened in the form ex- 

 hibited and here figured. The appa- 

 ratus after removal of the wings 

 drops into the closed chamber /, for 

 convenience of carriage, and the upper 

 vessel, of a known capacity, fits into 

 the lower one, after removing the sup- 

 ports by which it is held in place 

 when in use. The top vessel is filled 

 through the stoppered neck, whilst the 

 water is allowed to escape into the 

 lower vessel through an aperture near 

 to the bottom, which can be closed by 

 a solid indiarubber plug, vide Fig. 22. 

 These vessels may be made of any 

 convenient size, or the lower vessel, 

 or indeed both vessels, can be got rid 

 of, and the vane, supported by the 

 clamping-screw to a table, can be con- 

 nected to a large jar full of water, 

 placed on a chair, closed with a tight- 

 fitting cork, through which two tubes 

 pass, one to receive the end of the indiarubber tube, and the other 

 the short leg of a flexible siphon, reaching inside to the bottom of 

 the jar. 



The great object has been to combine in one instrument the vane 

 and aspirator forms, rendered as portable and of as little cost as 

 possible. If to be set up definitely at any particular spot, the dimen- 

 sions would necessarily be increased, and some form of aspirator used 

 that would draw regularly a measured quantity of air through the 



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