444 



Recollections of a Tour made in May, 1839, 



112 





^ 



113 



JJJ. 



side by side, as in fig. 111.; in 

 which a represents the first 

 course, and b the second 

 course. The bond, or tying 

 together of both sides of the 

 wall, is not obtained by laying bricks across (technically, headers), but by the 

 full-breadth bricks covering half the breadth of the broad bricks, when laid 

 over the narrow ones, as shown in the dissected horizontal sec- 

 tion fig. 111. at b, and in the vertical section^. 112. Besides 

 the advantage of being built fair on both sides, there being no 

 headers, or through and through bricks in these walls, when they 

 are used as outside walls the rain is never conducted through 

 the wall, and the inside of the wall is consequently drier than 

 the inside of a wall 9 in. in thickness. These walls are adapted 

 for a variety of purposes in house-building and gardening, in 

 the latter art more especially. The only drawback that we 

 know against them is, that the narrow or half-breadth bricks 

 must be made on purpose. 



ArnotCs Stove we saw here undergoing what appears a con- 

 siderable improvement ; viz. fixing to its sides vertical cast-iron 

 plates, 6 in. deep, and about 4 in. apart, for the purpose of in- ___ 

 creasing the surface, and consequently conducting away the heat 

 more rapidly. An idea may be formed of this improvement, by the vertical 

 profile of a portion of the top of a stove, fig. 113. The improvement is ap- 

 plicable to iron stoves of every description ; and, 

 of course, also to iron pipes heated to a high 

 temperature, with steam or hot water, in hot- 

 houses, or even to the bottom and sides of boilers. 



Cast-iron Heads to Rammers are also used in 

 this neighbourhood, instead of wooden ones ; and 

 they are adopted by the engineers on the rail- 

 ways and new roads now going forward in the 

 neighbourhood of Derby, though we observe 

 wooden ones still employed on the Birmingham 

 line. The cast-iron heads are made rather 

 smaller than the wooden ones in common use, 

 and of different degrees of weight, from 8 lb. the 

 smallest size, to 171b. the largest. 



Fig. 114. shows the form of the head of a rammer of the smallest size, into 

 which the handle is fastened by first splitting the end of the handle or shaft 

 and entering a small wedge in it, and afterwards inserting it in the socket of 

 the cast-iron head, and driving it home till it assumes the appearance shown 

 in the figure. In this section, the lower part of the socket is made somewhat 

 larger in diameter than the upper part, which makes room for the expansion 

 of the shaft at its lower extremity, occasioned by driving it home. 



Fig. 115. is a section of the head and lower part of the shaft of a rammer 

 of the largest size ; in which the socket for the shaft passes right through the 

 head, and is made fast there by driving in a wedge in the same manner as in 

 fastening the helve of an axe or a pick to the head. 



The advantage of these cast-iron rammers is considerable. In operating 

 with a wooden rammer, the workman, if lazy, lifts it up only a few inches ; and 

 his letting it fall at that height has no effect on the ground whatever ; but, if 

 the head is of cast iron, if he lifts it up at all, its coming down, if only a few 

 inches, will not fail to make an impression. It is wonderful, indeed, that this 

 improvement was not thought of before. Mr. Paxton has adopted these cast- 

 iron rammers at Chatsworth, and he finds them excellent. 



Cast-Iron Gutters to Roofs, as a substitute for leaden ones, are found eco- 

 nomical and effective. Fig. 116. is a section of a gutter between two roofs, 

 in which a a is the gutter, with a flange (b b) for joining the different pieces 





