In situations where gas is to be obtained, it forms a ready, and, for some purposes, very economical means of obtaining heat; its economy does not arise from its cheapness compared with other means, but from the fact that it need not be lighted till the instant it is required, and can be as quickly extinguished when it has done its required duty; for heating any vessels containing liquids, especially if the heat is required to be only of short continuance, gas will be found extremely advantageous; a ring burner, constructed as shown in _Fig. 2_, less than three inches in diameter, will quickly boil a gallon of water in a metallic vessel; burners of this description are usually used in the laboratory, surrounded by a case made of sheet-iron or tinned plate, as _Fig. 3_; this serves to support the vessel to be heated, to steady the jets of flame, and to conduct every portion of hot air against the bottom; the door also gives a ready access to the burner for the purposes of lighting the gas. [Illustration: _Fig. 3._] For the domestic use of gas in heating, we believe there is no contrivance so useful as the following:—A circular hole, from two to four or more inches in diameter, is cut in the dresser, through which is passed a sheet-iron tube, supported by three little elbows; this tube projects a few inches above the table, and about a foot and a half below; its lower end is open, and into it projects a gas pipe, furnished with a stop-cock; the upper extremity is covered with a sheet of wire gauze, similar to that used for blinds, on which, as shown in _Fig. 4_, may be placed some pieces of pumice-stone, surrounded and kept together by a broad ring—neither the pumice-stone nor the ring, however, are essential parts of the contrivance. The action of this arrangement is as follows:—When the gas is turned on it escapes from the pipe, rising through the tube, and mixing with the air contained within it; this mixture then escapes through the wire gauze, and may be lighted on its upper side, without passing through it to the gas below; the flame should be perfectly free from smoke, which indicates too much gas—should be pale, colourless, and not soil any bright metal placed in it; if the flame is in the slightest degree yellow it will do this, and then the gas should be partly turned off—on the contrary, if there is not enough gas, the flame will be extinguished. When lighted, the pumice becomes red-hot, and throws out a great heat; when used in boiling, the vessel should be supported a short distance over the flame by a trivet; if it is made to rest on the top of the ring, and is sufficiently large to close it entirely, the current is stopped and the flame extinguished, whilst the unburned gas still escapes below. This contrivance is most useful, it is lighted in an instant, is perfectly free from smoke, no unburned gas escapes, it throws out great heat, and may be employed to heat bright