242 



CASSELL'S POPULAE GAEDENIXG. 



some clear idea of the nature of the work and the 

 character of the tools needed for its performance. 

 In general terms, the lower portions of drains are 

 wholly excavated hy such narrow tools as Nos. 3, 4, 

 5, 6, 7, 8, and 9, Such tools not only reduce to a 

 minimum the amount of earth to be moved, hut hy 

 reducing the width of the drain to the narrowest 

 possible area, the tiles are gripped firmly by the 

 solid soil on either side of them and held immovable 

 as in a \T.ce. It is impossible to over-estimate the 

 importance of this in insuring the stability and 

 consequent permanent efficiency of tile drains. A 

 horizontal displacement of half an inch would reduce 

 the discharging power of inch tiles one half ; displace 

 an inch, and the drain would be blocked or stopped. 

 Hence the vital importance of a narrow base for 

 drains, and a firm wall of earth on either side of the 

 tiles. 



Solidity of Base. — This is the most important 

 in all drains, but very much more so in the case of 

 tiles than of those formed of bushes or stone. In the 

 latter an inch or two of subsidence here or there is of 

 less moment, though it may prove a serious danger 

 in any sort of drain. But with tiles of such narrow 

 bore, the danger increases as the tiles diminish in 

 size, until with inch only, the most common of all for 

 drainage, it becomes most serious. It is not so im- 

 minent in gardens as in fields, as in the former, pipes 

 of one and a half, two, two and a half, or even 

 three inches are often used. But it is equally im- 

 portant that in all drains the utmost care should be 

 taken to leave the base-lines that receive the tiles or 

 drainage material undisturbed. To this end great 

 care should be taken with the bottom spit not 

 to pierce the soil or subsoil one atom beyond the 

 tile-sole, for once the ground is disturbed no 

 future attempts at consolidation can restore its 

 primitive hardness. It is far better to leave an inch 

 or two at the base to be scraped out with the spoons, 

 No. 7 or No. 9. Occasionally, too, faults, fissures, 

 or gullies will be found in the bottom of the drain. 

 These should be filled in with stone or solid earth, 

 and made so solid that there should be no fear of 

 future subsidence. Tiles may also be had to order 

 of several times the ordinary lengths, so as to span 

 over soft spots or flaws in the strata, their ends 

 resting on the solid soil on either side. 



Figs. 21 and 22 are simple contrivances to measure 

 the size or depth of drains. Fig. 22, with its three 

 cross-bars, keeps the section of the drain from base 

 to summit of regular form throughout. Fig. 21 

 merely measures the depth, the cross-bar at top 

 resting on the surface on either side. This may 

 readily be made movable, so that this simple con- 

 trivance would measure the depth of any drain, 



and in cases where the surface has an even fall, it 

 answers all the purpose of a level, and no other will 

 be needed. Fig. 23 is the tile-layer, the long 

 handle enabling the drainer to reach the bottom of 

 the drain M'ith the tile on the holder c. It is 

 astonishing how rapidly tiles can be well and truly 

 laid by this handy contrivance in the hands of a 

 skilful workman. 



The Actual Catting and Laying of the 



Drains, — But little remains to be advanced on this 

 part of the subject, as it has been incidentally re- 

 ferred to in the description of tools. There is 

 one very useful lesson in drainage operations that 

 landscape and other gardeners may with much 



Fig. 21. 



Fiff. 22. 



Fig. 23. 



Fig. 21.— Stick vnth Movable Cross-bar for Measuring tbe 

 Depth of Different Drams. Fig 22.— Stake with Movable 

 Ci"oss-bar, and also Cross to Measure Width of Drain. 

 Fig. 23.— Tile Layer. 



profit take from farmers, "Wherever drainage 

 operations are extensive, it is so much cheaper, 

 as well as better, to have the plough remove the 

 first spit of the soil. Ha-\dng decided on the lines 

 of drains, a good ploughman will draw the lines 

 sufliciently straight and at regular distances 

 without more ado than the placing of a few poles 

 at the end of the land to be di^ained. A good section 

 of earth is also removed at the least cost, and the 

 workmen having got their work laid out before 

 them, there is no loss of time in starting. This 

 should always be done, the tiles laid handy and 

 convenient, the fall per ten or twenty feet de- 

 termined upon, and all adjustments of simple 

 working tools and tests provided before starting. 

 The advantages of all these preliminary arrange- 

 ments will result in the second spit being thrown 

 out before the first would have been settled about 

 under ordinary haphazard ways of going to work. 



"VMien the space is too limited or confined for the 

 plough, the drains should be all carefully set out. 



