404 An Apparatus for Ventilating Hot-Houses. 



a spindle, so as to turn with the changes of the wind, and if 

 the communication is to be made through the end of the 

 house, a transverse tube will be necessary. A drain cock {k) 

 is inserted in the bottom of the cylinder, in order that the 

 water may be drawn out, and replaced if air should get in by 

 the machine being shook. 



I am satisfied, from the precision with which this machine 

 acts, that it is not only perfectly competent to obviate all the 

 difficulties at present experienced in hot-houses, from sud- 

 den increase of temperature, but that in hospitals and other 

 buildings requiring ventilation, it may be applied with great 

 advantage. 



I am, Sir, 

 your very obedient servant, 



George Mugliston. 



Replon, near Derby, 

 March 24th, 1824. 



