242 ART OF BUILDING. 



because the brick being porous and dry, will absorb so 

 much of the water from the mortar as to prevent its 

 sticking. 



In building a wall of any kind, not more than four or 

 five feet of any part should be built at a time, because 

 as we have stated in our Tract on Heat, the mortar shrinks 

 on becoming solid ; and if one part of the wall shrinks 

 before the other it will cause a rupture. 



There are two kinds of bonds used by masons. Eng- 

 lish and Flemish. The English bond consists of a 

 course of bricks laid -lengthwise, then another under- 

 wise to the face of the wall. There is but one ob- 

 jection to this bond, which is the difficulty in breaking 

 joints, which requires that a brick should be broken at every 

 course. The Flemish method consists in placing a head- 

 er and stretcher alternately. This is deemed much neat- 

 er than the former ; but in the execution it has some in- 

 conveniences and is not thought to be so firm as the English. 



The masons of Boston adopt a different bond, they lay 

 five or seven courses of stretchers and then one of head- 

 ers. This, however, is thought by some, must yield to 

 the English and Flemish, not only in beauty and prac- 

 tice, but greatly in strength, because there is not a suffi- 

 cient bond between the two faces of the wall. 



In laying all kinds of stone masonry, it is of the utmost 

 importance that each stone should lay on its natural bed, 

 otherwise the joints will flush, and frequently the stone 

 will break ; a glaring instance of this may be seen in the 

 front of St Paul's church in Boston, where the stones are 

 ruptured, in consequence of this very fault. It is also of 

 the utmost importance that each bed of the material 

 should be perfectly level and smooth, otherwise the joints 

 will flush out and ruptures will be produced. 



Rubble stone masonry is such as is made of unhewn 

 stone ; it may be laid in courses, or in an irregular man- 

 ner. In coursed rubble, the stones are all gauged to the 

 same height, but in uncoursed rubble the stones are laid 

 promiscuously in the wall, only having the sharp corners 

 knocked off. 



The strength and durability of all masonry when it 

 has been laid in a proper manner, with good lime, de- 

 pends entirely upon the force with which the mortar ad- 



