MECHANICAL AND USEFUL ARTS. Ill 



of a pipe of 2 inch bore, it required a breaking weight to be applied 

 of i cwt. 1 qr. 13 lb. before the fracture was effected. — Engineer. 



PATENT WATER PURIFIER. 



The Reports of Mr. Arthur Aikin, F.G.S., and, in 1849, Dr. 

 Alfred S. Taylor, Professor of Chemistry in Guy's Hospital, went to 

 show that only one-fifth of a grain, or a sixteenth part of the whole 

 amount of organic matter, was arrested by the then best known 

 process. Since then chemists both at home and abroad have applied 

 their energies to find a remedy, but they almost one and all agree in 

 the admission that science has been, if not wholly baffled, very con- 

 siderably frustrated, in its attempts to arrive at a successful result. 

 But recently, however, "D. N.," a Correspondent in the Times, 

 inquired, "How water which is impregnated with lead could be 

 made wholesome ?" This elicited a reply from, as we understand, a 

 chemist of repute in Berlin, who wrote : " Fortunately this can be 

 easily accomplished by means of well-burnt animal charcoal, which 

 may be used either in the manner of the whiting recommended by 

 Br. Faraday, namely, by stirring up the charcoal in the water and 

 allowing it to subside, or by filtering the water through a vessel 

 containing the charcoal in coarse powder. An apparatus in a very 

 portable form has been recently invented for the purpose of applying 

 charcoal to the purification of water from both lead and organic 

 matter. Dr. Letheby has tested it very severely for the Drinking 

 Fountain Association, and has reported very favourably of its action. 

 It can be easily attached to the supply pipe of a cistern, and thus 

 used at the time of drawing the water." 



The composition thus used as a purifying medium is a mixture of 

 animal charcoal, silica, and iron ; and although it is sufficiently 

 porous to permit water passing through it as rapidly as by any known 

 method of filtration, it does not allow of the impurities penetrating 

 below its extreme surface, from which they can be removed at any 

 period by a brush or cloth. The solidity and indestructibility of this 

 purifying medium is a guarantee against its becoming deteriorated or 

 out of order. 



It is but justice further to state, that it is the invention of a Mr. 

 Dahlke, a native of Berlin, who has further got the testimony of 

 Dr. Lankester to its entire efficiency; and that the low price at which 

 it is about to be publicly introduced as a portable apparatus for 

 domestic use, for travellers and for emigrants and others, places the 

 fact of the ingenious inventor's desire to give the utmost circulation 

 to its beneficial objects in the most favourable light. — Mechanics' 

 Magazine. 



NEW WASHING MACHINES. 



The Board of Guardians of the parish of Hampstead, together 

 with the medical officer of health, the master of the workhouse, 

 and its matron, have been employed in a series of experiments to 

 test the relative merits of certain Washing Machines, with a view to 

 the selection of the most effective. The one upon which their choice 



