53 o THE POPULAR SCIENCE MONTHLY. 



rior to hair-felt as a non-conductor. By preventing radiation of 

 heat from steam and hot-air pipes, this felt effects a large saving 

 in fuel and gives dry steam at long distances from the boiler, and, 

 by preventing excessive warmth of the boiler-house, adds much 

 to the comfort of the workmen. The felt also finds application 

 as a sheathing for covering wood-work in positions exposed to 

 heat, and for fire-proofing flooring, shelving, partitions, and the 

 like. 



As far back as 1850 the Chevalier Aldini of Milan, experi- 

 mented with asbestus, mainly with the object of turning it to 

 account in the manufacture of asbestus cloth, but little success 

 was met with until twenty years later. The unctuous character 

 of the substance and the extreme fineness of the ultimate fiber 

 are obstacles in the way of making asbestus cloth that shall be 

 strongly coherent and not pull asunder easily. These difficulties 

 appear to have been overcome to a great extent, and now in the 

 form of woven fabrics there are many important applications of 

 asbestus. To one of these, in particular, the attention of the 

 public is frequently directed, because of the numerous fatal fires 

 reported in theatres, music-halls, and similar places of entertain- 

 ment. In the great majority of theatre fires the flames begin in 

 the stage curtains or drapery. When these are made of asbestus, 

 of course they are incombustible ; or, if the curtain alone be of 

 asbestus it affords a means of separating the stage from the body 

 of the theatre, and, in case of fire in the former, prevents its 

 spread to the auditorium. Asbestus curtains are now in use in 

 the principal Roman theatres, and in many theatres in German, 

 English, and American cities, much to the advantage of the 

 theatre-going public. The mineral is also made into gloves, 

 stockings, and other garments ; in fact, complete suits of asbestus 

 clothing can be obtained. In Paris the firemen of the city have 

 recently been furnished with entire suits of asbestus cloth, and it 

 is said to be probable that London will soon follow the example 

 of the French capital. 



In the form of gloves it is of much service to stokers and 

 furnace-men, and as salvage blankets it is of great value. It is 

 announced that mail-bags will, in the near future, be of asbestus. 

 The frequent loss of mail matter by fire, in connection with rail- 

 way accidents, renders it desirable that some incombustible mate- 

 rial be used for this purpose. 



Much of the lower grade of asbestus is ground up with other 

 materials and made into cement and paint. The former is exten- 

 sively used as a non-conducting covering for boilers and steam- 

 pipes. Being a cement, it can not be readily removed without 

 much labor and loss, so that it is somewhat less convenient than 

 the felt, which, as already mentioned, is used for the same pur- 



