102 Transactions of the American Institute. 



great distinction as an inventor in the applications of heat. He is best 

 known as the founder of the Kuinford professorship in Harvard Uni- 

 versity, thp: Rnmford medal of the American Academy, and the cliief 

 agent in the founding of the Royal Institution of Great Britain.) 

 His oven was an iron cylinder heated from without, and provided with a 

 supply of hot air which might be regulated. It may be regarded as 

 the gei'm of tlie cooking-stove and range. He conceived the idea of 

 accomplishing in confined space what, previous to his time, had only 

 been attained before an open fire. He subjected the meat throughout 

 to heat, not high enough to scorch the surface, until the interior of 

 the pieces had experienced the requisite modification to render them 

 acceptable to the taste, and then introduced air heated to a tempera- 

 ture that would promptly brown the surface, causing the destructive 

 distillation which is essential to produce the savor of Avell roasted 

 meats. Tlie meats so prepared were considered not inferior to the 

 best roast meats produced by slowly revolving them before an open 

 fire, and required very much less fuel. 



Improved Ovens. 



The brick oven, especially designed for baking bread, has been 

 greatly improved in the direction of economy of fuel and labor. I 

 will call your attention to the plan of the Aerotherme, introduced 

 about a quarter of a century ago in France, which surrounds the oven 

 by trunks of heated air, maintaining, like the Kumford iron oven, a 

 constant and regulated temperature. [The lecturer here explained 

 several diagrams prepared to illustrate the operation of an Aerotherme.] 

 At the Paris Exposition there were several mechanical bakeries in 

 operation. One of them, a French device, had a series of open work 

 shelves, each of the shape of a sextant, attached at the junction of the 

 radii to a vertical shaft, by means of which the shelves could be swung 

 over a bed of coals or into heated space, and kept there till the bread 

 or biscuit was baked, and then carried round ^to the point of com- 

 mencement to be discharged. Another, of American invention, had 

 the shelves suspended in a huge, opeii work cylinder, in which their 

 horizontality could be maintained, while, by the revolution of the 

 wheel, they could be carried over the bed of coals, baked and returned. 

 The Vienna oven is an Aerotherme, to which two important additions 

 are made : one to admit steam into the oven during the process, so as 

 to maintain a moist atmosphere down to the last few minutes of 

 the 1:)aking, and the other a separate fire from which radiant heat, of 



