In one respect this mill demonstrates how easy it is for one to imagine a trouble and then spend a lot of money to correct a trouble that really has no existence.
It was known, of course, that a band saw under stress would be inclined to gravitate to the rear. In this mill the attempt is made to prevent this and compel the saw to follow its proper path around the wheels by raising or depressing the tail end of the top wheel shaft; and in order to do this automatically a steel trolley was applied to the rear edge of the saw, closely following it, whatever its position might be; but any movement of the trolley towards the front or rear was followed by a corresponding adjustment of the tail box of the top shaft. The effect of the trolley on the edge of the saw was bad; and besides that there really was no special need of any device of the kind.
In connection with this mill there are also three other interesting features worthy of mention, as one of them in particular illustrates the method then prevailing of preventing a log from rubbing or dragging against the saw when the carriage was run back or being gigged for the next cut. At the present time an off-setting mechanism is applied to the carriage trucks, but previously a depressor, so-called, was applied to all mills substantially as shown in the Wilkin mill and others illustrated herein. That is to say, both the upper and lower saw guides were movable transversely, and the off-bearer by means of a hand lever, forced the guides back from the saw line, carrying the saw sideways away from the log, and in this manner contact with the face of the log was prevented; but it was hard on the saw.
In this mill, however, there is a new departure as shown by the application of two small friction rolls or pulleys behind the saw, in place of the usual saw guides; the idea being to force the saw out to the saw line by means of the rolls, and then when the carriage was gigged the rolls were moved back and the saw permitted to fall away from the face of the log; this feature being an imitation of the same thing embodied in the Allington mill previously built at Saginaw, but not shown herein. This arrangement, however, proved to be severe on the saws, because such short bends will crack them in a short time, and besides this the rolls made such a roar in a mill that not much else could be heard.
Next in this mill a spring was employed to maintain a sensitive automatic strain on the saw; and this, like the other special features of the mill, proved worthless, and the mill, like the Allington, went out of use and is unknown to the art now.
Now in all the preceding it is shown that Saw Mill Machinery Builders were studiously striving during all the years between 1880 and 1887, and some of them to a much later date, to produce a Band Mill for sawing logs that would do good work and as much of it as lumbermen would be satisfied with, and that, too, without so much cracking and breaking of saws. The simple fact that they were continually devising new constructions with a statement each time that now they had struck it, and the further fact that without an exception all of these were entirely abandoned and fundamentally new machines brought out at a later date, prove indubitably that all of their former efforts had failed to meet the full requirements which lumbermen expected and demanded.
The question then naturally arises, how did it come about that successful cutting band mills of a wholly different type are now universally in use? Who is the man who originated the strictly modern band mill that served as a pattern for all to follow? The following will explain it:
Aug. 23 and Sept. 13, 1887, patents were issued to D. C. Prescott, then of Marinette, Wis., for improvements in Band Saw Mills, and other patents followed shortly thereafter on further improvements.
D. C. Prescott in 1887