MECHANICS AND USEFUL ARTS. 69 



nary way. This process -is the more deserving of attention at present, 

 quite independent of the superior quality of the pins, in consequence of 

 the exceedingly high price of brass wire. Bulletin dc la Sociefie d'Eti- 

 couraffement, 



ON THE APPLICATION OF THE GASES OF BLAST FURNACES. 



Mr. Xowel, in a recent communication to the Socity of Arts, made 

 some statements of interest respecting the practical application of the gases 

 of blast furnaces. It was shown, on the authority of Bunsen and Play- 

 fair, and from calculations deduced from data furmshed by the posthu- 

 mous papers of Dulong, that of the heat produced by the combustion of 

 the fuel in a coal-fed blast furnace, only 18.5 per cent, is realized in 

 carrying out the processes of the furnace, the remainder, 81.5 per cent, 

 being lost. This loss, in well-conducted establishments, is no longer per- 

 mitted. The gases are now collected at the mouth of the furnaces and 

 conveyed, by large pipes, underneath the boilers of the engines and round 

 the hot-air stoves. The principle has been carried out in great perfection 

 at Cwm Celyn. : the pipes gffe six feet in diameter, and are lined with fire- 

 brick ; and the gases from two furnaces only more than suffice for the sup- 

 ply of seven boilers, and for the hot blast for both furnaces, at a saving of 

 full ten thousand tons of coal a year. 



NETV ENGLISH STANDARD WEIGHTS AND MEASURES. 



It will be remembered, that the destruction of the Houses of Parlia- 

 ment by fire, in 1831, proved fatal to the standard yard and pound. A 

 commission was subsequently appointed to consider the steps to be taken 

 for the restoration of these standards, the members of which were all 

 Fellows o the E,oyal Society. 



The late Mr. Baily took a very active part in the preparation of a 

 standard yard ; which, however, although constructed most carefully, 

 deteriorated in such a manner as to be unworthy of confidence. Since 

 Mr. Baily's death, the Rev. Mr. Sheepshanks has been engaged on the 

 very difficult and delicate task of constructing a standard yard, while 

 Professor Miller, of Cambridge, undertook to make a standard avoirdupois 

 pound. The liberality of government placed at Mr. Sheepshanks' com- 

 mand apparatus for his purpose far superior to that possessed by his prede- 

 cessors. His labors were carried on in the lower tiers of cellars in Somer- 

 set House, which are very favorable to the work on account of their 

 slow-changing temperature. 



After an infinite number of experiments and comparisons, two stand- 

 ards have been constructed. The originals have been inclosed in one of 

 the walls of. the new Houses of Parliament ; and perfectly accurate 

 copies have also been placed in the custody of the Royal Society. 



The standard yard measure is defined by the interval between two lines 



