528 Transactions of the American Institute. 



agitation gives to each hair a progressive motion toward the root, but 

 the roots are disposed in different directions — in every direction — and 

 the lamellae of one hair will fix themselves on those of another hair 

 which happens to be directed a contrary way, and the hairs become 

 twisted together, and the mass assumes the compact form which it was 

 the aim of the workman to produce. If the wool is in cloth and sub- 

 jected to the process of fulling, the fibers which compose one of the 

 threads, whether of the warp or woof, assume a progressive move- 

 ment ; they introduce themselves among those of the threads nearest 

 to them, and thus, by degrees, all the threads become felted together, 

 the cloth is shortened in all its dimensions, and partakes both of the 

 nature of cloth and felt." No language can be employed which will 

 convey- a more correct and vivid impression of the process of felting 

 than the foregoing. 



Through the indomitable perseverance of Mr. Youatt, the author 

 of a valuable treatise on British sheep-husbandry, Monge's theory was 

 finally demonstrated, although he was often frustrated, and almost 

 yielded to despair, from the imperfections of his instruments. The 

 construction at last of a superior achromatic microscope by Mr. Pow- 

 ell, of London, enabled him to realize his ardent wishes, and his 

 description of the scene, and the conclusions to which he arrived, are 

 of too much interest to admit of any abbreviation. 



" On the evening of the 7th of February, 1855, Mr. Thomas Plint, 

 woolen manufacturer, resident at Leeds ; Mr. Symonds, clothing 

 agent, of London ; Mr. Edward Brady, veterinary surgeon ; Mr. 

 Powell, the maker of the microscope ; and the author himself, were 

 assembled in his parlor. The instrument was, in Mr. Powell's opinion, 

 the best he had constructed. A fiber was taken from a fleece of three 

 years' growth ; the animal was bred by and belonged to Lord West- 

 ern. It was taken, without solution, and placed on the frame to be 

 examined as a transparent object. A power of 300 (linear) was used, 

 and the lamp was of the common flat-wicked kind. The focus was 

 readily found, there was no trouble in the adjustment of the micro- 

 scope, and after Mr. Powell, Mr. Plint had the first perfect ocular 

 'demonstration of the irregularities in the surface of the wool, the 

 palpable proof of the cause of the most valuable of its properties — 

 its disposition to felt. The fiber thus looked at assumed a flattened, 

 ribborj-like form. It was of a pearly gray color, darker toward the 

 center, and with faint lines across it. The edges were evidently 

 hooked — or, more properly, serrated ; they resembled the teeth of a 

 fine saw. These were somewhat irregular in different parts of the 



