194 farmers' and mechanics' journal. 



References, 

 Fig. 1, — A, the Hopper. 



B, the Sweep, to which the horse is attached. 



C, the Spur, or Cog-wheel. 



D, the Nuts, or Mashes. 



E, the Key, which keeps the cog-wheel when grind- 

 ing, and which is removed when the pomace is to 

 be pressed. 



F, the Spur-wheel, attached to the screws, and i« 

 moved by the larger one. 



G, the Screws. 



H, the Follower, or Piston. 

 I, II, III, Side-pieces to the vats. 

 K, the end of the Vat. 

 Fig. 2, — is a representation of the Cog-wheel and Screws. 



ON THE CONSTRUCTION OF FIRE-PLACES. 



BY N. ARNOTT, M. D. 



During my attendance lately in some cases of pulmonary dis- 

 ease, while considering how best to attain the important objects of 

 uniformity of temperature, and the prevention of draughts or cur- 

 rents of air in the apartments to which the patients chiedy confined 

 themselves, a simple means occurred to me, which, on trial, per- 

 fectly succeeded. It is an addition easily made to any fire-place ; 

 and as its uses are important to the health and comfort of all the 

 inhabitants of cold climates, I am happy to suggest it to the public. 



It is simply a glazed metal frame-work, or window, placed be- 

 fore the fire, and coming in contact with the chitnney-piece and 

 hearth all round, so as perfectly to cut ofT communication between 

 the room and the fire-place ; and the fire is fed with air brought by 

 a tube from without. 



Completely to understand the eflfect of it, it may be remarked, 

 that of the heat produced by the combustion of fuel in a common 

 fire-place, a part radiates into the room as the light does, and the 

 remainder ascends the chimney with the smoke. That which fiuds 

 its way into the room, contrary to common apprehension, is pro- 

 "bably not more than a fourth part of the whole heat produced ; 

 but even less than this would be sufficient to preserve in the room 

 the desired temperature, could it be all retained. The great cur- 

 rent of air, however, in the chimney, carries this heat again quickly 

 with it, (for it is the warm air of the room passing away,) and a 

 chimney of the ordinary proportion, and with the ordinary velocity 

 of the smoke, will allow the whole air of the apartment to pass out 

 by it in less than half an hour. 



