594 THE POPULAR SCIENCE MONTHLY. 



antly until the oxidation of the great air-chamber proved that the 

 engine burned iron as well as coal at a ruinous cost. 



Although no mention is made by Rumford of such destruction of 

 the blow-pipes, he was evidently conscious of the costliness of his 

 original roaster, as he describes another which may be economically 

 substituted for it. This has an air-chamber formed by bringing the 

 body of the oven-door so as to inclose the space occupied by the blow- 

 pipes shown in Fig. 1, and placing the dripping-pan on a false bottom 

 joined to the front face of the roaster just below the door, but not ex- 

 tending quite to the back. An adjustable register door opens at the 

 front into this air-chamber, and when this is opened the air passes 

 along from front to back under the false bottom, and rises behind to 

 an outlet pipe like that shown at v, Fig. 1. In thus passing along the 

 hot bottom of the oven the air is heated, but not so greatly as by the 

 blow-pipes, which, being surrounded by the flame on all sides, are 

 heated above as well as below, and the air in passing through them is 

 much more exposed to heat than in passing through the air-chamber. 



To increase the heat transmitted in the latter, Rumford proposes 

 that " a certain quantity of iron wire, in loose curls, or of iron turn- 

 ings, be put into the air-chamber." 



This modification he called a " roasting-oven," to distinguish it 

 from the first described, the " roaster." He states that the roasting- 

 oven is not quite so effective as the roaster, but from its greater cheap- 

 ness may be largely used. This anticipation has been realized. The 

 modern " kitchener," which in so many forms is gradually and steadily 

 supplanting the ancient open range, is an apparatus in which roasting 

 in the open air before a fire is superseded by roasting in a closed 

 chamber or roasting oven. Having made three removals within the 

 last twelve years, each preceded by a tedious amount of house-hunting, 

 I have seen a great many kitchens of newly-built houses, and find that 

 about ninety per cent of these have closed kitcheners, and only about 

 ten per cent are fitted with open ranges of the old pattern. Bottle- 

 jacks, like smoke-jacks and spits, are gradually falling into disuse. 



When these kitcheners were first introduced, a great point was 

 made by the manufacturer of the distinction between the roasting and 

 the baking oven ; the first being provided with a special apparatus for 

 effecting ventilation by devices more or less resembling that in Rum- 

 ford's roasting-oven. Gradually these degenerated into mere shams, 

 and now in the best kitcheners even a pretense to ventilation is aban- 

 doned. Having reasoned out my own theory of the conditions de- 

 manded for perfect roasting some time ago (about 18G0, when I 

 lectured on " Household Philosophy " to a class of ladies at the Bir- 

 mingham and Midland Institute), I have watched the gradual disap- 

 pearance of these concessions to popular prejudice with some interest, 

 as they show how practical experience has confirmed this theory, 

 which, as already expounded, is that the meat should be cooked by the 



