BUILDINGS AND BUNGALOWS. 149 



down to a compact mass. Shingles, or " slates " 

 split from a straight-fibred tree, are very widely 

 used. But "not one-half the persons who lay 

 shingles have a correct idea of making a roof that 

 will be absolutely rain-tight during a driving storm," 

 says the Canadian Mechanic. The correct rule for 

 laying shingles of any length, in order to form a roof 

 leak-tight, is to lay the courses less than one-third 

 the length of the shortest shingles. For example, 

 when shingles are 18 inches long, many of them 

 will not be more than 17 inches in length ; there- 

 fore 5 inches is all that the course will bear to be 

 laid to the weather with surety of forming a good 

 roof. The shingles must be three thicknesses over 

 the entire roof. If they are not three thicknesses 

 if now and then a shingle lacks a quarter or half 

 an inch of being long enough to make three thick- 

 nesses there will in all probability be a leaky place 

 in the roof at such a point. Moreover, when the 

 lower courses lack half-an-inch of extending up far 

 enough to receive the rain from the outermost 

 course, in case the middle course were removed, 

 it would be just as well to lay them 7 inches 

 or 8 inches to the weather as to lay them only 

 5 inches or 5J inches. Many shingles are only 

 1 6 inches long, and many that are sold for 16 inches 

 long will hardly measure 15 inches. In this case 

 if the roof be rather flat, say about one quarter 

 pitch 4J inches is as far as they should be laid to 

 the weather. In case a roof were quite steep, it 



