Iron tells of a new style of fire-bar devised by an English inventor to secure fuller combustion of fuel. The peculiar feature of their bars is the shape of the spaces left for the air to pass through. These, instead of being straight, are of a wave-shaped form, the convex parts of one bar fitting into the concave parts of the adjoining one, and the proper distance being regulated by the width at the ends in the usual way. Additional oblong air-spaces are also provided, and placed in the spaces between the wave-shaped openings. The under side of the bars is made as thin as possible, so as to give the air ample inlet area; and when they have to be fitted against the sides of boiler-flues, a set of tooth-like projections is cast on to the edge of the outside bars. Any portion of the length of these teeth can easily be cut off by a hammer and chisel to effect the desired fit. By the use of these bars the inventor claims a large saving in fuel. - Polytechnic Review.