MECHANICS AND USEFUL ARTS. 63 



means of this fan by connecting a perforated pipe, placed underneath 

 the middle deck, to its discharge. This pipe may also be connected 

 to a second perforated pipe, placed on the lower deck, and connected 

 to a vertical pipe which communicates with the atmosphere. 



An apparatus similar to the one just described, but without the 

 condenser, may be applied to the concentration and crystallization of 

 sirups and saline solutions, the form of the boiler being, of course, 

 modified so as to assume the appearance of the ordinary fan ; and in 

 some cases the bottom is made corrugated, to form continuous zigzag 

 channels, through which the steam circulates, for the purpose of in- 

 creasing the heating surface. Hunt's Merchants' Magazine. 



Apparatus for Filtering Sea-water, M. Cardan has presented to the 

 French Academy a description of a new filter, intended to render sea- 

 water drinkable. The apparatus consists of a siphon, the long tube 

 of which is filled with powdered charcoal. The author states that 

 sea-water in traversing this siphon loses its nauseous savor, and that 

 the saline taste which remains is scarcely to be detected after mixing 

 with wine. London Atlicn&um, July. 



CENTRIFUGAL PUMP. 



THE Scientific American, for Jan. 26, describes a centrifugal pump, 

 the invention of Mr. Schmidt, of New York. There are two circular 

 flanges, which are bolted together, and form a hollow ring, within the 

 circumference of which are two disks also bolted together, so as to 

 form a hollow chamber within this hol]ow ring. This ring has an 

 orifice for discharge, to which a pipe may be attached, and a pipe from 

 a lower orifice on the other side communicates with the water in the 

 well or other place. A shaft rendered air-tight runs through the 

 pump, and, being connected with a pulley set in motion by a band, it 

 causes to revolve the arms of the pump, and thus forces up the water. 

 The ends or blades of the pump-arms run in the hollow ring, while 

 the arms themselves revolve between the sides of the disks. They 

 are fitted to run with ease, so that the passages do not get clogged 

 with sand, gravel, &c. This pump is stated to have been adopted at 

 several of the works of the government. They can be made capable 

 of discharging from 5 to 5,000 gallons of water per minute. 



NEW PUMP FOPv. MINES. 



SOME experiments have recently been made at the factory of Messrs. 

 Donkin & Co. on a new pump, designed for raising water from mines 

 or other deep levels, by direct action, without the intervention of main- 

 rods, buckets, plungers, or valves. The machine used for showing the 

 action of .the pump wa.s a one-horse power Bishop's disk engine, 

 which possesses the extraordinary character of being applied either 

 as a steam-engine to drive machinery, or of being driven by other 

 machinery, to form a pump ; it consists of a short cylinder, placed 

 longitudinally, in which a disk with a projecting arm vibrates with a 

 rolling motion. It was actuated by a steam-engine of similar form. 



