WOOL. 197 



are essential. The felt cloths for piano hammers are often made from 

 the yarns of these woollen fibres. 



" Hog's Wool." This term is applied to wool fibres that are clipped 

 from the lamb during its first shearing. These fibres are characterised by 

 a curly appearance and pliable staple, and are adapted to spin a high 

 class of counts. The basal parts of the fibres, at their insertion, have a 

 tendency to cohere together and assume a tufty appearance. 



Fig. 123 shows fibres of Hog's wool that have an excessive amount of 

 flexuosity and curliness. 



Irish Wool. This is often a mixture of wool and hair of a coarse 

 nature, depending very much upon the pasturage in which the sheep is 



Fig. 121. Spines of Medick (magn.). 



grazed. The sheep which inhabit the plains of Ireland are larger in size 

 than ordinary, and are noted for their unusually long-stapled wool, which 

 has lately been much more used in quantity and improved in quality. 



Northumberland Hog's Wool Fibres. Fig. 124 shows fibres of 

 Northumberland wool as it appears when taken from the sheep's back. 

 The fibres do not show the imbrications very clearly owing to the 

 presence of the yolk. Some are darker, and interrupted here and there 

 by particles of impurities that have adhered between the natural yolk 

 and the fibres of the sheep when living and browsing on the herbage. 

 The imbricated scales are shown pretty clearly, but the fibres are not of 

 one uniform thickness. 



