BUILDING MATERIALS. 249 



quarries from which we receive the granite in this country are in 

 Aberdeenshire and Argyleshire in Scotland, in Cornwall and Devon- 

 shire in England, and also in the islands of Guernsey and Jersey. The 

 best granite is received from Peterhead, in Aberdeenshire, and it is 

 of a reddish colour. A large amount of granite is now received from 

 Argyleshire in Scotland, and Guernsey and Jersey, for paving pur- 

 poses. The quality of granite varies very much, some kinds being quite 

 brittle and others very compact. The quality depends very much on the 

 size of the particles of which the stone is composed. Thus the best 

 stone will be found with the particles fine, closely packed together, and 

 uniformly distributed throughout the mass. Where the stone is very 

 hard and brittle, great difficulty will be experienced in dressing it, and 

 there it will be found that the predominating substance is quartz. If 

 felspar is abundant in the rock, the quality will not be first-class, as 

 it gives way to the action of the atmosphere ; an over-abundance of 

 mica has also the same effect therefore the best stone will be found 

 where the three substances are equally divided throughout. The cost of 

 Aberdeen granite, delivered in London, was, in 1867, 4s. fid. per foot 

 cube in blocks ; and for sizes suitable for paving it was 2s. 6d. 



2. Sandstones. Sandstone is the principal stone found in the Silurian 

 system, and is found over a great portion of this country. Some of the 

 principal sandstone quarries are to be found near Leeds and Whitby in 

 Yorkshire, Portland in Dorsetshire, and Craigleith and Dundee in Scot- 

 land. Sandstones are generally found of two classes, the grey and the 

 red, both of which are known as freestones. Their principal composition 

 is quartz in small particles, kept together by a calcareous cement. 

 These stones are very durable, and are much used for building purposes. 

 Some kinds of sandstone are very porous, and when saturated with 

 moisture in the winter season, the frost causes the stone to split up in 

 pieces. This kind of sandstone should not be used for building. It 

 will be found that the red sandstone has not this defect so much as the 

 grey. I have always preferred using the sandstones for the purposes of 

 coping, water-tabling, and corner-stones, and using other stone for the 

 main building. The most simple way of finding out the propensity of 

 any stone to take in water is to immerse a portion in water, and 

 take the weight of it before and after being in the water. This will 

 tell how much it has taken up. A large portion of Edinburgh has 

 been built of sandstone from Craigleith quarry. Among the chief build- 

 ings erected with this stone may be mentioned the College, Register 

 Office, National Monument, and also several churches. The Craigleith 

 stone has also been exported to Hamburg and other places on the 

 Continent. The cost in the quarry is from 9d. to 2s. per foot, in 



