PROCEEDINGS OF THE COTTESWOLD CLUB 287 



lbs. per sq. in. 



Newiy ------- will crush at 13,440 



Aberdeen Granite - - - - „ 10,900 



Purbeck „ 9,160 



Limestone „ 7,700 



Yorkshire Flag ----- „ 5>7I4 



Derby Grit „ 3, 'OO 



These tests speak for themselves, and demonstrate the 

 remarkable, almost extraordinary toughness of the Glee 

 Hill Basalt, the highest, other than Glee Hill, being 

 Penmaenmawr stone, crushing at 26,837 lbs. per square 

 inch. 



Granite, however, on roads is liable to have its com- 

 ponent parts broken up by friction, and is not so tough as 

 the more dense Dhu Stone, the specific gravity of granite 

 being 2"62 as against 2*867 i^"" ^^e case of the Glee Hill 

 Stone. 



The toughness of the stone is due to the large propor- 

 tion of hornblende it contains, and the absence of any 

 approximation to brittleness is also proved by these 

 tests. 



Sandstones and Limestones are readily crushed, and in 

 fact pulverized, and thus the metalling is no sooner laid 

 than it begins to grind down; dust and mud follow, the 

 latter has to be scraped off at great expense, and the road 

 soon again renewed. Such like stones and inferior trap 

 or igneous rock are frequently used, and more or less 

 rapidly perish. 



Although it is very enticing and apparently very 

 economical to pick up the material for roads at your 

 door, and so save expense of rail and road carriage, 

 the ultimate cost becomes greater than would have been 

 the case if a good and possibly expensive stone obtained 

 from a distance had been used in the first instance. 



Quite apart from the ultimate money saving, two other 

 material benefits accrue, one that there is a good road for 



