BUILDING AND ORNAMENTAL STONES. 529 



These are all fine-grained stones with but little cementing material, 

 the individual grains of which they are composed being held together 

 simply by the cohesion induced by the pressure to which they were 

 subjected at the time of their consolidation. They therefore work 

 very readily, especially when newly quarried, and have been used 

 more extensively for carved work than any other of our sandstones. 

 They are best represented in the market to-day by the so-called Euclid 

 " blue-stones " and Berea " grits " of Ohio, the former being deep blue- 

 gray in color, while the latter is very light. They are well known to 

 the general public in the form of window stools and caps, door posts 

 and steps, for which purpose they have been very extensively used in 

 all our large cities. 



Somewhat resembling in general appearance the Euclid blue-stones, 

 but of greater geological age, are the dark, blue-gray compact "gray- 

 wackes," or flag-stones, so extensively quarried in Ulster County, New 

 York, and other parts of this State and Pennsylvania. These stones 

 are of fine and even texture, and split readily from the quarries in 

 slabs, usually but a few inches thick. They are therefore eminently 

 suited for flagging, to which usage they are extensively applied, 

 though they also used for steps and general trimming purposes. The 

 rock quarried at Barryvale, in Sullivan County, is of a similar nature. 

 It was from quarries at this last-named locality that was taken the 

 monster flag-stone, twenty-five feet two inches long, by fifteen feet 

 wide and eight inches thick, that now forms a portion of the sidewalk 

 in front of the Vanderbilt residence on Fifth Avenue, New York. It 

 should be stated, however, that the size of this block was limited only 

 by the means of transportation, and much larger could be obtained at 

 the quarries if desired. 



Another very important group of sandstone, but of still greater 

 geological antiquity, belonging to the Medina period of the Upper 

 Silurian formations, is quarried extensively at Albion and Medina, 

 near Rochester, New York. These stones are usually of a reddish 

 color and contain a larger portion of siliceous cementing material than 

 any of those yet mentioned ; they are therefoi'e much harder and 

 much less pervious to moisture. The stones are used for all manner 

 of building purposes, flagging, and street-paving. A somewhat simi- 

 lar stone, but of brighter color and Potsdam age, is quarried in the 

 town of Potsdam, in St. Lawrence County, in the same State. This is 

 the stone used in the construction of the Columbia College buildings 

 in New York city. 



Sandstones of this nature, i. e., with the larger proportion of sili- 

 ceous cementing material, are among the most durable of all our build- 

 ing-stones ; but their extreme hardness, and often poor colors are great 

 drawbacks to their extensive use. In process of dressing such stone 

 an exceedingly fine white dust arises and remains for a long time sus- 

 pended in the air, to the great inconvenience of the workmen, who tell 

 vol. xxvn. 34 



