116 



to the soil those constituents which, as analysis points out to 

 the inquiring mind, become exhausted by such treatment. 

 Could this table be used in conjunction with an analysis of 

 the soils on which his efforts are to be employed, the agricul- 

 turist might indeed feel that science had opened to him a 

 prospect of almost boundless improvement in the results of 

 his labour; and it could no longer be said that ''Agriculture 

 " owed nothing to Chemistry." 



At the Evening Sitting, the following Paper was read : — 



ON THE RECIPROCAL PROPELLING POWERS OF FLUIDS, 

 AND CERTAIN ROTARY MACHINES UPON EACH OTHER. 

 BY B. BIRAM, ESQ., WENTWORTH. 



The object of this communication is to elucidate the 

 principle of action and proper construction of those rotary 

 machines which derive their motion from the oblique impulse 

 of fluids, as in the vertical windmill ; or which, on the other 

 hand, are capable of giving motion to fluids by an oblique 

 impulse; being themselves propelled by some other source 

 of power. 



Since the introduction of steam power, wind, as a prime 

 mover of machinery, has been comparatively little thought 

 of ; yet, from the abundant supply which often sweeps over 

 the land, and from the great economy of its application, it is 

 well deserving of consideration. We find, however, that 

 little has been done for a long series of years towards the 

 improvement of this description of power; that nearly the 

 same form of windmill sail is still adhered to which the 

 illustrious Smeaton found to be the best; and that the employ- 

 ment of wind for driving machinery, instead of progressing, 



