88 ANNUAL OF SCIENTIFIC DISCOVERY. 



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carved decorations and plaster cornices. When Frederick II. of 

 Prussia set up a limited papier-mache manufactory at Berlin, 1765, 

 he little thought that paper cathedrals might, within a century, spring 

 out of his snuif boxes, by the sleight of hand of advancing art. At 

 present, we old-fashioned English, who haunt cathedrals and build 

 churches, like stone better. But there is no saying what we may 

 come to. It is not very long since it would have seemed as impossible 

 to cover eighteen acres of ground with glass, as to erect a pagoda of 

 soap bubbles ; yet the thing is done. When we think of a psalm 

 sung by one thousand voices, pealing through an edifice made of old 

 rags, and the universal element bound down to carry our messages 

 with the speed of light, it would be presumptuous to say what can 

 and what cannot be achieved by science and art, under the training 

 of steady old Time. 



QUARTZ CRUSHING MACHINE. 



A NEW and very well contrived machine has been constructed in 

 New York, by Mr. John A. Collins, for the purpose of extracting 

 gold from quartz rocks. On a round cast iron plate, which forms the 

 bed plate of the machine, six or more conical wheels, whose axes con- 

 verge toward the center, are made to travel round, and to crush in 

 their way the pieces of rock which are put under them. The neces- 

 sary pressure and the motion are given by an ingenious contrivance, 

 which consists of another "circular plate resting on the wheels, and 

 which is fixed by keys on the axis, this axis being put in motion by a 

 steam engine. Above the second plate is a third, connected with the first 

 by vertical columns, and held down to the required pressure by india- 

 rubber springs, so that if a piece of rock is harder than the others, 

 the wheel, rising over it, presses the springs, which give back a 

 stronger counter pressure, sufficient to crush the piece ; at least, it 

 prevents any danger of breaking the machinery. 



By the above arrangement, there is no friction in the machine, 

 either by rotary axes, or by sliding pieces. There is only rotation 

 of wheels on plane surfaces, so that very little power is consumed by 

 the machine itself. There are necessary contrivances to make a cur- 

 rent of water pass over the powdered rock. 



LATH CUTTING MACHINE. 



THE following is a brief description of a lath cutting machine 

 invented and patented by Henry C. Smith, of Cleveland, Ohio. 



A series of rotating knives are keyed into a cylinder, which is 

 placed over the log to be cut. The cylinder is one foot in diameter, 

 and the length of the log is four feet. Grooves are planed in this 

 cylinder, about one inch deep, for the reception of the knives. These 

 knives, when placed in the cylinder, are of such width as to set out 

 from its face one-half of an inch, and arc some twenty-five in number, 

 being placed the width of the lath apart, and are the length of the log or 



