3 14 Mtthodef increajing the Heat of Fires, 



nefs. Hence it appears that a red-hot burning coal does not fend ofFnear fo many calorific 

 rays as a piece of redhot brick or ftone, of the fame form and dimentlons ; and this inte- 

 refting difcovery will enable us to make very important improvements in the conflruttion of 

 our fire-places, and alfo in the management of our fires. 



The fuel inftead of being employed to heat the room direSily, or by the dire£l rays from 

 tlie fire, fliould be fo difpofed, or placed, as to heat the back and fides of the grate s which 

 muft always be conftru£ted of fire-brick, or fire-done, and never of iron, or of any other 

 metal. Few coals, therefore, when properly placed, make a much better fire than a larger 

 quantity ; and fhallow grates, when they are conftrufted of proper materials, throw more 

 heat into a room, and with a much lefs confumption of fuel, than deep grates ; for a large 

 mafs of coals in the grate arrefts the rays which proceed from the back and fides of the 

 grate, and prevents their coming into the room ; or, as fires are generally managed, it 

 prevents the back and fides of the grate from ever being fufficiently heated to affift much in 

 heating the room, even thongh they be conftrufted of good materials, and large quantities 

 of coals be confumed in them. 



It is poflible, however, by a fimple contrivance, to make a good and an economical fire 

 in almoft any grate, though it would always be advifable to conftruft fire-places on good 

 principles, or to improve them by judicious alterations, rather than to depend on the ufe 

 of additional inventions for correcting their defe£ts. 



To make a good fire in a bad grate, the bottom of the grate muft be firft covered with a 

 Cnglc layer of balls, made of good fire-bricks, or artificial fire-ftone, well burnt, each ball 

 being perfedly globular, and about 2f or 2i inches in diameter. On this layer of balls the 

 fire is to be kindled, and, in filling the grate, more balls are to be added with the coals 

 that are bid on ; care muft, however, be taken in this operation to mix the coals and the 

 balls well together, otherwife, if a number of the balls (hould get together in a heap, they 

 will cool, not being kept red hot by the combuftion of the furrounding fuel, and the fire 

 will appear dull in that part; but if no more than a due proportion of the balls are ufed, 

 and if they are properly mixed with the coals, they will all, except it be thofe perhaps at 

 the bottom of the grate, become red-hot, and the fire will not only be very beautiful, but 

 it will fend off a vaft quantity of radiant heat into the room ; and will continue to give out 

 heat for a great length of time. It is the opinion of feveral perfons who have for a confi- 

 derable time pradlifed this method of making their fires, that more than one third of the 

 fuel ufually confumed maybe faved by. this fimple contrivance. It is very probable that, 

 witli careful and judicious management, the faving would amount to one half, or fifty 

 per cent. 



As thefe balls, made in moulds, and burnt in a kiln, would coft very little, and as a fet 

 of them would laft a long time, probably feveral years, the faving of expence in heating 

 rooms by chimney fires with bad grates, in this way, is obvious ; but ftill, it {hould be 

 remembered that a faving quite as great may be made by altering the grate, and making it 

 a good fire-place. 



In 



