Vol. VI JULY, 1917 No. 6 B EDITORIAL CHAT Criticism ROADLY speaking, there are just two kinds of criticism, CON- and DE-structive, and it is difficult to conceive that two brands of the same product could produce such diametrically opposite results. The right kind of criticism, the constructive kind, has been a constant stimulus to progress since human endeavor began, for if possibilities of improvement had not been seen and indicated, there would have been no improvement. Constructive criticism is essential to development in every field of effort-art or science. The other kind, the DE-structive kind, the mean, carping, flawfinding variety that offers no substitute for that which it condemns, succeeds only in breeding discouragement and resentment and so clogs the wheels of progress. Enthusiasm cannot survive it, and without enthusiasm little is accomplished. Stand and look at some great manufacturing plan. Ponder the fact that every step in its growth, every improvement in process or product, was the result of criticism-but don't forget which kind it was. Quality S O far as we know, the immense structure shown above is the largest ever built of logs. It was erected at the time of the Lewis and Clark Exposition at Portland, Oregon, and the wood used is the famous Oregon fir. (Taxus Brevifolia) From "American Forest Trees" Copyright Hardwood Record T HE Pacific yew is an interesting tree, useful for many minor purposes, but it is not procurable in large quantities. Its north and south range covers more than 1,000 miles, from Alaska to central California; while the species occurs from the Pacific Coast eastward to Montana. It approaches sea level on some of the Alaskan islands, and toward the southern part of its range it reaches an altitude of 8,000 feet. In Idaho it is called mountain mahogany, but apparently without good reason. Its color may bear some resemblance to that wood, but it is different in so many particulars that the name is not appropriate. The names western yew and Pacific yew are used interchangeably. Sometimes it bears the simple name yew; but since there is a yew in Florida, and another in Europe, it is well to give the western species a name which will distinguish it from others. The northwestern Indians called it "fighting wood," which was the best description possible for them to give. They made bows of it, and it was superior to any other wood within their reach for that purpose. In fact, if they could have picked from all the woods of the United States they could scarcely have found its equal. It is very strong, though in elasticity its rating is under many other woods. It is of interest to note that five hundred or more years ago the European yew (a closely related but different species) had nearly the same name in England that the northwestern Indians gave the western yew. It was called "the shooter yew," because it was the bow wood of that time, and "bow staves," where were rough pieces to be worked out by the bow makers, were articles of commerce. The search for it was so great and so long continued that yew trees were well-nigh exterminated in the British Isles. It was, next to oak, and possibly above oak, the most indispensable wood in England at that time. It is instructive to observe that Indians who used the bow found the western yew as indispensable in their life as the English armies found the European yew at a time when the bow was the best weapon. The northwestern Indians put this remarkable wood to other They made spears of it, (Continued on Page 93) uses. Effect of Too Heavy Feed on Circular Saws A LMOST invariably when breakage occurs at the center of circular saws it is only after they have been giving satisfactory service for periods ranging from one run to several months. Obviously, if there were anything inherently wrong in the make-up of a saw it would be almost impossible to get even one full run out of it. This leads to a consideration of operating conditions which might cause breakage across the center after the saw is in service. By far the most common cause is too heavy feed and the mechanical effect of this on the saw is the subject of this article. In the first place, saws broken from this cause are broken only after they have left the line and run out of the cut. As soon as this occurs the action is identical with that of a wedge driven between two objects; and the heavier the feed, the greater the force of the wedge, and consequently the strain on the blade. No operator, of course, intentionally forces his saw out of the cut, but an anxiety for an extra large output for a record cut sometimes leads to an attempt to carry more feed than any saw The tre could stand up under. mendous pressure brought on the blade as soon as it leaves the cut subjects it to strains entirely beyond its tortional strength. When this occurs, one of three things must happen. Either the carriage would have to be pushed bodily off the track, the mandrel would have to be thrust endwise back from the log or the saw would have to give way. As the saw is by long odds the weakest point of the three, it is almost invariably the one to suffer under these conditions. While this breakage usually does not occur during the early runs of the saw, it quite frequently happens that saws are slightly forced over the collar, and as a result take a bend at that point. This may happen several times before the breakage takes place, but the elasticity and strength of the saw is reduced with every bend and every hammering it receives. It must be borne in mind that when the rate of feed is so heavy that the gullets of the saw cannot take care of and pocket the sawdust removed and a considerable portion of this dust is forced to (Continued on Page 94) |