During the past few weeks, a highly interesting experiment--and one, moreover, destined to materially influence the development of the uses of gas in a fresh field--has been in progress, under the guidance of Mr. Booer, at a baker's shop in the Blackfriars Road, London. The experiment in question is nothing less than the application of gas for heating bakers' ovens, in a manner not hitherto attempted, and such as to bring the system within the means of the poorest tradesman in all but the smallest towns. It will be remembered that the success of the gas-heated muffles for burning tiles and glass led to the attempted construction of a model baker's oven, heated by the same fuel, which was shown in action at the Smoke Abatement Exhibition at South Kensington in the winter of 1881-82. This model attained considerable success; but its design demanded either a new structure in every case, or considerable alteration of any existing oven. In the proposed system, moreover, the oven was heated wholly from without--a condition supposed to be necessary to meet the objections of the bakers. It is evident, however, that there must be considerable waste of gas in heating a mass of tiles and brickwork, such as go to the construction of a common baker's oven, from the outside; and the objection to handicapping such a costly fuel as gas in this manner becomes more apparent when it is remembered that in the usual way the oven is always heated by an internal coal fire. When it is further considered that the coal commonly used by bakers is of the most ordinary quality, full of dirt that would condemn it in the estimation of a gas manager, the sentimental objection to allowing a purified gas flame to burn in a place which this rubbish is permitted to fill with foul smoke becomes supremely ridiculous. Consequently, when Mr. Booer, whose work in connection with the gas muffle is well known in England and America, seriously addressed himself to construct, upon altogether new lines, a cheap and practical baker's oven, he wisely put the gas inside.