CHAPTER XXVI 



MASON WORK. CEMENTS, PAINTS, GLUES AND WAXES 



ANY material that sets or hardens when dry is a cement ; and under 

 this general name may therefore be included glues and materials used for 

 mending or sticking together broken articles. As commonly used, 

 however, the word cement now refers to building or construction 

 material, used by masons. 



The formulas here given are largely for home-made compounds, 

 and many of them are old-fashioned. 



Building or Mason's Cement ; Gravel, and Pitch 



Two kinds of building cement comprise the common construction 

 grades in this country, natural-rock cement (Rosendale), and port- 

 land cement. The former is made from limestone containing much 

 clay; the material is burned at a low heat, and is then ground. It 

 is a quick-setting cement. The portland cement (named from Port- 

 land Island on the south of England) is an artificial mixture of some 

 form of carbonate of lime, with some clay, burnt at white heat and then 

 ground. The natural-rock cements are light-colored, and weigh 

 from fifty to sixty pounds to the cubic foot. The portland cement is 

 dark-colored, and weighs from ninety to one hundred pounds to the 

 cubic foot ; it is one-half to twice stronger than natural-rock cements. 



Approximate estimates of mason-work. 



Three and one-half barrels of lime are required to cover 100 square 

 yards plastering, two coats. 



Two barrels of lime will cover 100 square yards plastering, one coat. 



One and one-half bushels of hair are needed for 100 square yards 

 plastering. 



One and one-fourth yards good sand are required for 100 square yards 

 plastering. 



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