VARIATION IN THE STATE OF THE HAIR. SOS 



On the 3l8t of March, 1810, certificates were received T««ain4omesrf 

 from Mr. John Rice, Cotton-End; Mr. J, Hawkins, 

 Castle-Ashby ; and Mr. William Shaw, Hardin g^stone, to 

 the following effect : viz. — That they Ivad purchased of Mr. 

 William Jeffery, and nnade perfect trials of his newly- 

 invented expanding harrows, and find them to be upon a 

 tnuch superior principle to any they have seen, or made use ,'^ 



of before. 



Reference to Mr. W. Jeffery's Expanding Harrows. 



Fig, 3, PI. VIU, represents Mr. Jcffery's expanding bar- The !^imnr 

 row. It consists of two sets of movable bars of wood, con- ^*^ 

 nected by hooks in one set, and eyes in the other. Each set 

 is composed of four bars of wood, A B C D, furnished with 

 teeth; these are connected, and held parallel to each other 

 fey three other bars, or braces, E F G, united to the former 

 by screw bolts ; the iron loops H I are the points for the 

 chains, by which they are drawn; K are two iron braces, 

 joined to the bars E at one of their ends, and have a nutn* 

 ber of holes, any of which can be put over screw-pins fixed 

 upon the middle bar F, provided with nuts; when these 

 nuts are removed, and tlie iron braces detached from their 

 pins, the frames may be either closed up, or extended, so 

 as to bring the teeth of the harrow nearer together, or Te- 

 ttiove them farther asunder, and they, can be fastened at any 

 point by the different holes in th6 irOn braces, so as to be 

 worked with the teeth at any requisite degree of extent. 



XHI. 



Observations on an occasional Increase and Decrease of 

 Bulk in the Hair of the Head. In a Letter from Tho- 

 mas FORSTER, Esq, 



To Wm. NICHOLSON, Esq. 

 SIR, 



At has always appeared to me, that the best means to get Knowledge 

 Sit a correct knowiedge of any intricate subject is, to excite e*'"*^ *»y«*- 



the 



