BUILDING AND OENAME^nTAL STONES. 327 



Cc) LATHES AND PLANERS. 



For turuiug posts and pillars lathes are uow very generally used for 

 granite as well as for softer stone. In easy working varieties, as sand 

 s\one, limestone, or serpentine, the cutting tool is a simple chisel, much 

 like that used in turning metals, and held in a clamp iu the same nuin- 

 ner. With the harder rocks, like the granite, however, this method is 

 inefifectualj and the cutting tool is iu the form of a thin steel disk some 

 G or 8 inches in diameter, which is so arranged as to revolve with tlic-, 

 stone in the lathe when pressed against it at a sharp angle. By tliis 

 means large aud beautiful columns can be made at far less cost than 

 by the old hand processes. 



A monster machine of this character, seen by the writer in the Vimil- 

 haven quarries in 1880, is capable of taking a block 25 feet in length 

 aud 5 feet in diameter and turning it down to a perfect coluiun. 



With the softer varieties of stone a, plain surface, sufliciently smooth 

 for flagging, is produced bj* means of planing-machines similar to tliose 

 in use for planing metals. For doing tlic same work on hard nuiteiia! 

 like granite a planer, witli revolving cutting disks of chilled iron, simihir 

 to those used in the lathes, lias been de\ise(l. This machine is shown 

 in the accompanying figure, page 328. 



(Ci) MACHINES FOR SAWING. 



In sawing marble and other soft stones the same method, with some 

 modifications, is employed as was in use, according to Professor Seeley,* 

 three hundred years before the Christian era. 



The principle consists simply of a smooth fiat blade of soft iron, set 

 in a frame aud fed with sharp sand and water. The saws are now fre- 

 quently set in gangs of a dozen or more in a single frame, and several 

 gangs are tended by one man, who shovels on the wet sand as it is 

 needed, while tine streams of water from overhead wash it beneath the 

 blade as it swings backward and forward in its slowly dee]>ening groove. 

 Some attempts at automatic feeders have been made, but they are not 

 as yet in general use. 



This method has been found inapplicable to cutting granite, owing to 

 the greater hardness of the material. Keceutly a sand composed of 

 globules of chilled iron has been used to good advantage. Tiie great 

 drawback to the use of this material, so fiir as the author has observed, 

 is the care necessary to avoid staining the stone by rust from the wet 

 globules during the time the machine is not running. This is done by 

 wetting down the stone and globules in the saw frame with a thick so- 

 lution of lime-water (whitewasii) prior to leaving the saws for the 

 7'ight. Circular saws, with diamond teeth, have been used to some ex- 



* The Marble Border of Western New England. Proc. Middlebury,.Hist. Soc. Vol. 

 I, Part II, p. 28. 



