Proceedings of the Polytechnic Association. 873 



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one (if it could be made) of a diameter equal to tlie lengtli of an ordi- 

 nary log, at a cost of hundreds of dollars, and a thickness of not 

 less than half an inch. 



2d. Its Continuous Motion. — A subject, however, too well under- 

 ^stood to need further commment. 



3d. Its Straight line Action^ ' and at the same time, its capa- 

 bility of being adjusted to any angle of the wood, as in the case of 

 the hand-saw. Every sawyer knows that the manner in which a 

 circular saw enters the wood, at first dead against the grain., and 

 from that gradually working its way out in a quarter circle, is the 

 very hardest process of doing the work, and consequently requires 

 the most power. All this is entirely overcome in the endless chain. 



4th. The limited Extent of Injury hy Accident. — As the destruc- 

 tion or damage of two or three teeth only involves the section of 

 which they are a part, tliat section can be replaced by a new one in 

 a few minutes, without any injury to the rest of the saw. If the 

 obstruction be of a character to destroy a circular saw, or tear out 

 every adjustable tooth, the section of this saw encountering it, would 

 break, and the saw stop ; tJie hroken section heing the only loss. 



5th, Tlie smcdl P 010 er Ilequired. — For two reasons; first, it cuts 

 ^oit}^, the grain ; and, second, the edge of the saw is but a small distance 

 from the center of the motion. If the lower wheelJ, whicli drives the 

 saw, be twenty -four inches in diameter, it is equal to a circular saw, 

 that will cut hut nine inches into a log, wdiereas this saw can be 

 extended upward four feet, without increasing the distance of the 

 teeth from the center of power. 



6th. Its Economy in Wood. — As it is held in tension, it can be 

 made much thinner, and thereby cut more hoards from the same log, 

 than the circular saw ; the gain being about ten per cent. 



7tli. Its Great Saving in Wear and Tear of Machinery, as it 

 requires much less speed. This saw works from pure force or 

 strength ; M'hereas a large share of the cutting ability of the circular 

 saw is from sheer momentum. 



8th. It forms a perfect planer by setting and sharpening the sides 

 of the teeth on every fourth or fifth section. 



9th. It is made of tempered steel, and ground to a catting edge. 



10th. It can be furnished at far less cost than the cii-cular saw, and 

 as the sections for the largest kind of saw can be packed in a very 

 small compass, it is easy of transportation, and not liable to damage. 



The Chairman remarked that the two largest circular saws exhi- 



