DRAINING. 



DRAINING. 



drain to a river be too small, and there be risk, 

 at times, of the overflowings of the river send- 

 ing back-water into the drain, the drain should 

 be carried down as far by the side of the river 

 as will secure a sufficient fall for the outlet. 

 Rather be at the expense of carrying the drain 

 under a mill-course or rivulet than permit back- 

 water toenter it. 



A spirit level 

 (see cut) has been 

 found a very con- 

 venient instru- 

 ment for ascer- 

 taining such 

 point, and gene- 

 rally for taking 

 levels in fields. It 

 is furnished with 

 eye-sights a b, and 

 when in use is 

 placed into a 

 framing of brass, 

 which operates as 

 a spring to adjust 

 it to the level po- 

 sition rf, by the 

 action of the large 

 headed brass 

 screw c. A stud 

 is affixed to the 

 framing, and 

 pushed firmly 

 into a gimblet- 

 hole in the top 

 of the short rod 

 e, which is pushed 

 or driven into the 

 ground at the spot from whence the level 

 is desired to be ascertained. It need scarce- 

 ly be mentioned that the height of the eye- 

 sight from the ground is to be deducted 

 from the height of observation, and which 

 quantity is easily obtained by having the rod 

 marked off in inches and feet; but it may be 

 mentioned that this instrument should be used 

 in all cases of draining on level ground, even 

 where one is confident that he knows the fall 

 of the ground, for the eye' is a very deceitful 

 monitor for informing you of the levelness of 

 ground. Such a spirit level, well finished, 

 costs in England, 15 shillings, (about $4). Its 

 whole length is 8 inches, depth 1J inches, 

 width or breadth, 1 inch. It is so light as to 

 admit of being carried in the pocket, whilst its 

 rod may be used as a staffer cane. 



The cutting of the main-drain should be en- 

 tirely finished before the tiles are laid in it; and 

 immediately after it is finished, it should be 

 measured with the drain-guage, to ascertain 

 whether it contains the specified dimensions 

 and fall. This drain-guage is an excellent sub- 

 stitute for the tape-line or foot-rule, which are 

 both inconvenient for the purpose of measur- 

 ing the dimensions of a drain. This simple 

 instrument consists of a rod divided into feet 

 and inches, with two arms fixed cross-wise, the 

 length of which is to correspond with the re- 

 quired width of the drain. When this rod is put 

 down to ascertain the depth, it is afterwards 

 turned partially round, whilsl its end rests on 

 the bottom of the drain, until the ends of its arms 



touch the earth on both sides. If the arms can- 

 not come round square to the sides of the drain, 

 the drain is narrower than intended ; and if 

 they cannot touch both sides, it is wider than 

 .necessary. When made larger than intended, 

 a greater expense may be incurred in filling up 

 with stones, &c. 



The person intrusted with the laying of the 

 soles and tiles into drains, should be one who 

 has been long accustomed to that kind of work, 

 or otherwise a good workman, possessing judg- 

 ment and common sense. He should remain 

 constantly at the bottom of the drain and have 

 a boy or other assistant to hand him the tiles 

 and tools. After laying three soles in length, 

 he must examine to see if they are straight in 

 the face, and neither rise nor fall more than the 

 fall in the drain. As a safe guide to him, where 

 the fall is not decidedly cognisable by the 

 senses, a mason's plumb-level will be found a 

 convenient instrument. After three soles are 

 thus placed, two tiles are set upon them, being 

 so placed that their joinings shall meet on the 

 intermediate spaces betiveen the joinings of the 

 soles. 



The tiles for small drains are usually made, 

 according to Mr. Stephens, about 3 inches 

 wide and 5 inches high, inside measurement, 

 which may be considered a large tile in places 

 where those of 2J inches wide by 3$ inches 

 high are used. The soles for small drains are 

 made of different breadths, varying from 5 to 7 

 inches. They usually shrink about one-eighth 

 in the kiln. 



Several ingenious and efficient machines 

 have been invented in Great Britain, which 

 have greatly facilitated the manufacture of 

 drain tiles and soles, and reduced their cost to 

 the very moderate prices stated in the esti- 

 mates presented. In the 12th volume of the 

 Prize Essays and Transactions of the Highland 

 Agricultural Society, descriptions of some of 

 these will be found, illustrated with drawings. 

 That invented by the Marquis of Tweeddale, 

 and for which a gold medal was awarded him, 

 will make 12,000 tiles in a day of ten hours, 

 it being understood that the clay is previously 

 prepared and milled, as in the common way, 

 when three or even four men can only produce 

 1500 tiles in the same time. The machine re- 

 quires a power only equal to one horse, and the 

 assistance of one man and two boys, one of 

 these to feed in the clay and two to remove the 

 tiles to the shelves. 



The Essays, in the same volume, of Mr. 

 Boyle and Mr. Taylor, upon the manufacture 

 of draining tiles are well worth the attention 

 of persons particularly interested in the sub- 

 ject, as they not only treat of the minutiae 

 of the operations, but are illustrated with 

 very numerous figures of the implements, 

 mode of placing the tiles in the furnace, 

 &c., &c. 



Much capital has been wasted in the erection 

 of tile-works, by those who have not at first 

 known the best modes of proceeding, and em- 

 ployed men to manage them who knew little 

 about the processes. Like most other kinds 

 of business, tile-making and baking require a 

 regular apprenticeship, in order to succeed 

 properly. As the machine of Mr. Beart has 



415 



