852 Transactions of the American Institute. 



making wood type, cutting the forms of the letters, but not producing 

 relief, as in other machines. 



Dr. Blanchard — My machine does not require skilled labor ; it is 

 automatic. Ten or twelve cutting points can be applied at once. 

 With two points it will cut in marble ten superficial feet, two inches 

 deep, in ten hours, using four-horse power. A cylindrical surface 

 may be cut with equal facility. 



Mr. Kelly stated that the work done with Mr. Bull's machine was 

 more delicate than the sample produced. 



Dr. Blanchard explained that the sample was cut in a very soft 

 stone, and was not intended to show the capability of the machine in 

 cutting a fine stone. 



Mr. Charles T. Porter added the explanation that the pattern 

 itself, in this case, was of wood, and not delicately finished. 



Mr. J. K. Foster suggested that the principle of giving drills a 

 high speed might be applied to great advantage in tunneling. 



Dr. J. W. Richards suggested the use of this machine for forming 

 spectacle lenses. 



Mr. Raynor stated that in slitting the iridium points of gold pens, 

 18,000 revolutions per minute are required. 



Dr. Blanchard (in reply to MJ\ Fisher) stated that his machine 

 would either enlarge or diminish the size, if desired. 



The President remarked that this was peculiarly an American 

 invention, and narrated the manner in which the original Blanchard 

 lathe came to be invented. 



The same inventor presented the following papers : 



Roofing. 

 By V. W. Blanchard, M. D. 

 In this invention I do not claim any new form or mode of con- 

 structing a roof. I only claim a cheap, durable, fire-proof roofing 

 material. In this invention, the soft, cheap varieties of wood, such 

 as poplar, sapling pine, whitewood arid other varieties of a similar 

 character, whose loose, soft fiber unfits them for ordinary shingle, are 

 first cut into the form of the ordinary taper shingle or slate. These 

 are then passed between two toothed rollers, in a bath of coal tar 

 heated to about 300 degrees F. These rollers are so arranged that 

 their teeth may be made to penetrate or perforate the wood to any 

 desirable depth. They are also arranged in the alternate or quin 

 quick order, so as to cut as much of the grain of the wood as possible. 

 By this means, the wood treated in the manner described may be 



