26 EVENINGS AT THE MICROSCOPE 



simply beaten, pressed, and worked together, between damp 

 cloths. The same property enables woven woollen tissues 

 to become close and thick: every one knows that worsted 

 stockings shrink in their dimensions, but become much 

 thicker and firmer after they have been worn and washed 

 a little; and the " stout broadcloth," which has been the 

 characteristic covering of Englishmen for ages, would be 

 but a poor open flimsy texture, but for the intimate union 

 of the felted wool-fibres which accrues from the various 

 processes to which the fabric has been subjected. 



In a commercial view, the excellence of wool is tested 

 by the closeness of its imbrications. When first the wool- 

 fibre was submitted to microscopical examination, the ex- 

 periment was made on a specimen of Merino ; it presented 

 2,400 serratures in an inch. Then a fibre of Saxon wool, 

 finer than the former, and known to possess a superior felt- 

 ing power, was tried: there were 2,720 serratures in an 

 inch. Next a specimen of South-Down wool, acknowl- 

 edged to be inferior to either of -the former, was examined, 

 and gave 2,080 serratures. Finally, the Leicester wool, 

 whose felting property is feebler still, yielded only 1,850 

 serratures per inch. And this connection of good felting 

 quality with the number and sharpness of the sheathing 

 scales is found to be invariable. 



The hairs of many Insects are curious and interesting. 

 Here you may see the head of the hive-bee, which is mod- 

 erately clothed with hair; each hair is slender and pointed, 

 and is beset with a multitude of subordinate short hairs, 

 which project from the main stem, and stand out at an 

 angle: these are set on in a spiral order. Here again is 

 one of the hinder legs of the same bee: the yellow hair, 

 which you can see with the naked eye, consists of strong, 



