HOW ON LIMESTONE AND MARBLE. 61, 



Mr. Peters, the builder of the barracks, is my authority for this 

 character of the Chester rock and he tells me that the lime from it 

 is the only one yet found to his knowledge fit to use in making con- 

 crete. A black limestone is found at St. Peter's, Cape Breton, which 

 is said to afibrd most excellent lime. 



Hydraulic Limestones. — These are limestones which contain a 

 certain proportion of clay and sometimes magnesia and have in con- 

 sequence the valuable property of setting under water after being 

 burned to the proper degree.* These important minerals should 

 receive careful attention ; they are reported to exist in several parts 

 of the Province. Mr. G. Lang informed me last year that Shuben- 

 acadie affords a limestone the lime from which was used twelve 

 years ago in building a chimney for a steam-engine and that the 

 work under water cannot now be separated. He says now that this 

 lime takes the first place in the family of limestones on this continent 

 as affording a lime for mason work and for all exterior Avork. The 

 lime from it slacks with unusually little water and takes as much 

 sand again as any other used in the country, and makes a mortar 

 which is better than any cement except the Portland, made in Eng- 

 land, resisting the severe frosts and sudden thaws much better than 

 that made with lime from St. John or West Indian limestone. He 

 has burned about 300 tons and now has his kiln ready to burn about 

 2,000 tons. Hydraulic limestones are also reported from Windsor, 

 and from St. Peter's, Cape Bx'eton. 



Cement-stones are limestones containing foreign ingredients, which 

 when burned and ground can be made into cement. Mr. Handley, 

 of Halifax, showed me a cement he had used in putting together fire- 

 bricks, which he had made from a stone found near St. Peter's, 

 Cape Breton, by careful burning, grinding and mixing with sand in 

 certain proportions : he assured me it was a very strong cement. 

 Such stones are very valuable : during the construction of railways 

 and other public works in Canada one manufacturer made on the 

 average 80,000 bushels of cement annually. The limestones of 

 Walton and Teny Cape, in Hants Co., often contain magnesia, but 

 in what quantity is not known, nor have they been examined as to 

 their hydraulicity. A good deal of work on this subject awaits a 



*An excellent account of these is given in Weale's Series on "Limes and Ce- 

 ments." See also Chera. News, sii p. 287, and xiii p. 86, and Geology of Canada, 

 1863, p. 805, 



