[29] U. S. FISH COMMISSION STEAMER ALBATROSS. 31 



lever (by a cord not shown), when the bucket descends to the floor and 

 is again automatically stopped. The machine is noiseless and rapid in 

 its action, has worked with certainty, and has required but little atten- 

 tion. 



DISTILLING APPARATUS. 



The distiller, patented by the writer, is the kind generally used on 

 board American steamships. The object of the machine is to distil 

 drinking-water. There are three block-tin coils placed inside an an- 

 nular cast-iron cylinder, the coils terminating in manifolds which pass 

 through stuffing-boxes in the heads of the cylinder, as represented in 

 Plate XXI. To the top of the coils is screwed an air-injector a, which 

 is supplied with steam at b and air at c, the velocity of the steam in- 

 ducing the air current; the steam and air thus entering, molecule to 

 molecule, thoroughly mixed before condensation. The current of sea- 

 water, forced into the condenser at d, passing out at e, keeps the sur- 

 faces of the coils cool which condense the steam within. The fresh 

 water and air rush out of the coils at /and into a filter of carbo animalis 

 purificatus, from which it is delivered to the ship's tanks through the 

 opening g. The fresh water will absorb (dissolve) only a small portion 

 of the air (less than 2 J per cent of the volume under the pressure of 

 the atmosphere), but the large excess of air injected into the steam 

 serves to oxidize organic matter which is brought over by the steam, 

 and this especial filter is to remove those oxides. The object of the 

 annular jet of steam is to bring a larger surface of steam-jet in contact 

 with the air, and the object of the annular condenser is to compel the 

 circulating water to flow over the condensing surface. The filtering 

 material requires to be renewed about once in two years. The commercial 

 size of this machine is Xo. 4, and its capacity is 2,000 gallons per day ; 

 the daily consumption of water on board is about 250 gallons. A ton 

 of coal will distil about six tons of water, so there is a saving of weight 

 and space by employing the distiller on board ship. The quality of the 

 distilled water is always the same, and I quote the words of an eminent 

 medical director of the Xavy in saying that "diarrhea has diminished 

 50 per cent on board our ships since the introduction of distilled water." 

 The water is clear and, being well aerated, tastes quite as good as hy- 

 drant water; in fact it is difficult to detect it as the product of distil- 

 lation. 



LIGHTING. 



The operation of dredging, in great depths, sometimes* carries the 

 day's work past midnight, and after the contents of the dredge are safely 

 deposited on board, the naturalists are required to preserve the speci- 

 mens, which often takes two hours longer. To facilitate this the com- 

 missioner authorized the installation of the Edison incandescent system 

 of electric lighting. The plant consists of an8£by 10 inch Armington 



