The _Proceedings_ of the Institution of Mechanical Engineers contains a description of Frisbie's Mechanical Fire-feeder--a contrivance which economises fuel, increases heat, and saves trouble when applied to the fireplace of a steam-engine or furnace. Underneath the fireplace is a mechanism which carries a movable hopper; the hopper is filled with coal, and by the turning of a winch, is raised until the fresh coal is pressed against the bottom of the fire. The smoke, having to rise through an existing fire, is nearly all consumed; and the pressure from below breaks up the clinkers, and causes them to fall away to the circumference of the fireplace, from any part of which, as the bars are made to rotate, they can be easily removed. Among the advantages of this method are: that 'the fire is not reduced in intensity by the cold fuel damping the flame,' as is the case in fireplaces of the usual construction: that 'each successive charge of fuel lifts up and most effectually pokes the fire:' that 'the cooling of the furnace by the admission of a large volume of cold air when the fire-doors are opened for stoking, is avoided;' and that 'a smokeless flame is readily attainable with a thick fire, although using smaller fuel than can be employed in ordinary furnaces.' Accepting this information, it is not out of place to mention that the furnace by which steam is generated for driving the machinery by which this _Journal_ and our other works are printed, is fed upon a somewhat similar principle. Small coal (dross) is placed in a hopper at the near end of the furnace, and rests upon and is gradually carried into the interior and on to the far end (where it is dropped as clinkers) by closely connected parallel bars which traverse the furnace from end to end and slowly revolve round a 'drum.' The strength of the fire is regulated by a door, which may be raised or lowered by a winch, to admit of a greater or less supply of fuel, as necessity may indicate. The result is that combustion _begins_ at the near end of the furnace, the smoke is consumed before it can reach the flue, a steady fire is maintained without admitting an unnecessary amount of cold air or necessitating the constant attendance of a fireman, and the economical desideratum of a perfect smoke-consuming apparatus is achieved. The apparatus goes by the name of Jukes' Patent, and has been in constant use for over twenty years. In comparison with ordinary furnaces, a saving of seven per cent. of fuel is effected. Why this patent apparatus for prevention of smoke is not in universal use, we cannot explain.