OR, A TREATISE ON PILE. 155 



describe the modus operandi, the learned and the unlearned were equally at fault. The 

 skilful operator has a mass of wool, which, with his magic bow, he has formed into the 

 desired shape ; this fleece. " light as the thistle-down that floats on the air," with no other 

 agency than a damp linen cloth, and the pressure of his hands,* he, in a few moments, 

 transforms into a firm cloth or felt ; but neither he, nor the scientific looker-on, could 

 explain the phenomenon. At length a filament of wool was placed under the microscope, 



and THE MYSTERY WAS REVEALED. f 



It is the scales of the cortex of pile that cause the filaments to felt. They are circularly 

 disposed. Upon hair they are less numerous, smoother, rounder at the point, and embrace 

 the stalk more intimately ; upon wool they are more numerous, rougher, sharper at the 

 point, and at their anterior extremities stand a little out from the shaft. 



The scales from the different wools should be drawn, described and classified to under- 

 stand perfectly their felting power. 



The first attempt to count the number of these scales was made by Mr. Youatt. He 

 found upon a filament of Anglo-Merino wool, 2,400 to a linear inch. 



Let us here pause for reflection. If one inch, in length, of this wool has 2,400 scales, 

 and it is (as Mr. Youatt tells us) in diameter y^ of an inch, there are, upon the whole 

 area of its contour, 23,040 scales, ever ready to hook and fasten into as many to be found 

 upon every similar inch of filament with which it comes in contact !j Mr. Youatt after- 

 wards counted the scales of other wools, from the result of which we have made the 

 following- table : 



* The nitrate of mercury is sometimes used to facilitate the felting. 



t In an article published in the Plough, the Loom and the Anvil, for 1850, we have given a history of the discovery of the 

 cause of felting, and endeavored to do justice to the memories of those concerned in its discovery. 



J The following calculation was made for us by Ferdinand Hubbel, Esq. There are 2,400 points (which are the edges of 

 scales) upon one inch in length of Merino wool assuming it to be of the same circumference, there were 2,400 in the 

 contour, and multiplying 2,400 by itself, will give 5,760,000 for the number of points on the one inch of cylinder. But the 

 filament has a diameter of only y-j^ of an inch 7.22 ?is : : 0,004=- T ^5o == 2T7' 



Divide 5,760,000 by 250, and you will have 23,040 for the number of scales upon one inch in length of a filament of wool 

 that has a diameter of TJJ of an inch. 



