Paris, patented the plan of mounting band-saw wheels on pointed centres, with an improved grooved sawguide, mounted on double points, to keep the saw to its

FIG. 24.-KNOWLING'S PATENT BAND SAWING MACHINE.

work. In the same year Mr. McDowall, of Johnstone, patented a multiple band sawing machine. He claims the combining of two or more endless band saws in

one machine, so as to operate on the same piece of timber, making the standards of multiple band sawing machines adjustable, and mounting the pulleys on eccentric pins or studs, which can be adjusted for different thicknesses of cut.

Our illustration (fig. 24) represents a machine embodying several improvements which have recently been patented by Mr. Knowling, of Newton Abbott, Devon.

The chief points claimed as novel are:-In so constructing the machine that when the saw is canted for cutting at an angle, the table of the machine shall travel in a horizontal plane; undue strain on the saw is thus avoided, and the table carrying the wood is kept at a dead level. In most of the ordinary band sawing machines, when it is required to cut at an angle, the table carrying the wood is itself canted, and considerable difficulty is found in keeping heavy timber in position to be fed through the saw. The main frame of this machine is fitted at its base with trunnions, which work in the foundation plate. A screw is so arranged underneath the table, that, by means of the hand wheel shown in the engraving, the frame of the machine is canted, and the table moved at the same time. Another improvement consists in adjusting the tension of the saw by means of a pivoted arm or bracket, carrying the upper saw-wheel, which is acted on by a screw bedded on a spring support placed on a fixed rest. The patentee claims that the invention can be carried out in canting the saw by means of a screw, worm, or other mechanical contrivance, working on, or in, or against a movable metal frame carrying the pulleys actuating the band saw; the said movable

frame being journalled at its lower end, on the same centre as the bottom saw pulley. The table is moved by the same motion actuating the moving frame, which for that purpose is connected with it. The tension adjustment can be performed by constructing the brackets of metal or other material, furnishing the brackets with a spring or sliding bed, on one end of which a screw works, the other end abutting against a pivoted arm or bracket, carrying the upper saw pulley, so that the turning of the screw separates the pulleys and tightens the saw. In Western's and other patents several of the points herein mentioned have before been carried out separately, but the combined movement of saw and table is novel, and must be mentioned as a decided advance in this class of machines, and should be found of service to cabinetmakers, chairmakers, and others requiring to cut much bevelled work.

In the International Exhibition of 1878 held in Paris, a large number of band-saw machines were shown, most of them in operation. Although this machine was chiefly developed by the French, they, of most other nations exhibiting, seem to have made less progress in rendering it efficient and complete in its every detail. We will briefly notice such machines as possess any special feature of improvement in their design or arrangement.

In the English section perhaps the most original form of band saw was that exhibited by Messrs. Western and Co., of London, one of whose patents in connection therewith we have just described. To allow for the expansion and contraction of the saw blades, a Wilson's patent spring arrangement was added; this we have also spoken of before. Messrs. Charles Powis

and Co., of London, exhibited in their band-saw machine an improved method of canting the table for bevelsawing; it consists of a modified form of the ball-andsocket joint arrangement.

For general purposes perhaps the most complete machine in the Exhibition was that shown by Messrs. J. A. Fay and Co., of Cincinnati, Ohio, U.S.A. Its general construction differs considerably from English practice, and is well worthy of description, and we therefore illustrate it (fig. 25). As will be seen from the engraving, the main frame of the machine is a flanged casting, and is made in one piece. The rim of the upper saw-wheel is made of steel, the spokes of wrought iron, and the centre of cast, thus combining lightness and elasticity in the greatest possible degree, and reducing the strain on the saw. The saw-wheel spindles are of steel, and run in self-oiling bearings; these bearings are adjustable for wear; the saw is kept to its proper tension by means of a screw and hand wheel, and the top-saw spindle being fitted on a slide, the weighted lever shown at the back of the machine compensates for any expansion or contraction in the saw when at work. Three small metallic guide wheels receive the back thrust of the saw, which is also fitted with wooden side guides, and runs on indiarubber, let into the wheels, which are made without flanges. The top saw-wheel is arranged to angle. The vertical guide bar placed in the front of the machine is fitted with a retracting spring, which allows it to be readily adjusted to the thickness of the timber. The table is arranged to cant for bevel-sawing by means of a ball-and-socket arrangement. A combination of brake and striking gear allows the machine to be stopped and started gradually. A small brush