Book II. CANALS. 621> 



3828. If we compare our first, fourth, and fifth cases (3S24), we shall find in all of thera a water-tight 

 stratum, as the basis ; and the practice in these cases is to make a wall of puddle, called a puddle-ditch, or 

 puddle-gutter, within the bank of the canal : these puddle-gutters are usually about three feet wide, and 

 should enter about a foot into the water-tight stuff", on which they are always to be begun ; and they 

 should be carried up as the work proceeds, to the height of the top water-line, or a few inches higher. 

 Our second and third cases (3824) evidently will not admit of the above mode, because we have no water- 

 tight stratum on which to begin a puddle-gutter, as a bottom : in these cases, therefore, it is usual to apply 

 a lining of puddle to the sides and bottom of the canaL 



3829. History of puddling. It appears that the Dutch have been in the habit of 

 making mud ditches to secure the banks of their canals and embankments, from time 

 immemorial ; and that operations similar to our puddling have been long known on the 

 Continent, but it is not clear at what period it was introduced into this country. We 

 think that the fens in Cambridgeshire and Lincolnshire, in which so many works have at 

 different times been executed by Dutchmen, are the most likely places in which to 

 search for early evidence of its use. We cannot think that Brindley was the first who 

 ever used it in this country, although we might admit that the Bridgewater canal was 

 the first in n hich it was systematically employed as at the present day. 



3830. Adjustment of materials. Canals set out with the "care that we have recom- 

 mended, will always have the proper quantity of stuff to alluw foFi the. settlement of 

 the banks ; since the united sections of the loose banks will always equal the section of 

 excavation in the same settled or consolidated state in which it was before the digging 

 conimenced. The slopes of made banks, it is to be observed, on account of their settling, 

 should be steeper in the first instance than they are ultimately required to be. 



3831. T/ie letting of the cutting of certain lengths of the canal to contractors, who will- 

 employ a number of navigators under them, in digging and puddling the canal, is the 

 next business. 



3832. Tt is usual to let the work at a certain price per cubic yard of digging, and to pay for the puddling 

 or lining either at a certain pi ice per cubic yard or per yard run of the canal. The engineer ought to 

 inform himself thoroughly of the difficulties and facilities which attend the work he is about to let, and 

 to draw up a short but explicit contract to be signed by the contractor. The prices allowed ought to be 

 fair and liberal, according to the circumstances, so that the contractor may have no pretence, on account 

 of low prices, to slight his work, particularly the puddling ; and they ought in every instance to be strictly 

 looked after, and made to undo and renew immediately any work that may be found improperly per- 

 formed. We recommend it to the engineer to keep a strict account, by means of his overseers or counters, 

 of the time of all the men employed upon the works ; distinguishing particularly the number upon each 

 V7ork, and whether employed under the company by the day, or upon the work let to contractors. These 

 particulars are most essential towards knowing what money ought to be advanced to the contractor during 

 the progress of his job, and towards informing and maturing the judgment of the engineer, with regard to 

 the length of time that a certain number of men will be in performing any future work he may have to 

 direct. A calculation should also be made of the day-work in every instance, and compared with the con- 

 tract price, by which alone a correct judgment can be formed of tlie proper prices at which work ought 

 afterwards to be let, so that the labourers may receive wages i)roportionate to their exertions, and the 

 contractor be amply paid for his time, skill, and superintendence; and yet economy, and the interest of 

 the company, be duly consulted. 



3833. Barrows and wheeHng planks, horsing-blocks, and other implements, are generally found by the 

 company; and it is usual to consider twenty to twenty-five yards a stage of wheeling, and to fix a price 

 per cubic yard according to the number of stages that the soil is to moved. Where this distance exceeds 

 100 yards, it will rarely be eligible to perform it by wheel-barrows ; therefore runs of plank with an 

 easy descent, if the same is practicable, should be laid, for large two- wheeled barrows or trucks to be used 

 thereon. 



3834. Where the line of a canal is to cross an extensive stratmn of valuable brick earth, or one of good 

 gravel for making roads, it will often be advisable, especially if the line can be thereby rendered more 

 direct, when setting out the canal, to cut pretty deep into such materials, and even quite through the 

 gravel, if the same is practicable ; for although considerable expense will in the first instance be incurred 

 in digging and in damage done for spoil banks, yet such materials as good brick earth and gravel will, in 

 almost every instance, find a market as soon as the canal is opened. Such a situation may prove of essen- 

 tial service to the trade of the canal, by enabling the adjoining proprietors to work the whole thickness of 

 their brick earth, gravel, or other useful matters, with but little detriment to the surface of the ground, 

 and without being annoyed by water ; this the canal, instead of losing water by preserving a high level 

 through porous stuff, would, it is probable, catch in very considerable quantities. In districts where stone 

 and gravel for making and repairing roads are scarce, it will be proper to pay the labourers certain rates 

 per cubic yard for all the stones or gravel that may be collected by them during the work, and stacked in 

 proper places. These will form resources for making the towing-path, and for making good the landing 

 or ascent to the several bridges, and the several pieces of new road that the engineer will have to form 

 near to the canal bridges. The lock banks, and all wharfs and landing places, should also be covered with 

 good gravel, to render them safe and convenient for use. If good gravel can in places be intersected in 

 deep cuttings, much of the above expense, as well as that of cartage, may be saved, by an early use of 

 dirt boats in the bottom of the canal. 



3835. How important and various the duties of the resident engineers are, must have 

 struck every reader ; but it would be much more apparent, could we enter into the sub- 

 ject of reservoirs, feeders, aqueducts, embankments, culverts, safety gates, weirs, tunnels, 

 deep cuttings, locks, substitutes for locks, inclined planes, railways, bridges, towing- 

 paths, fences, drains, boats, towing or moving boats and trams, cranes and implements ; 

 but these, as less important for our purpose, we must leave the reader to study in the 

 works of Philips, Fulton, Chapman, Plymley, Badeslade, Kindersly, Anderson, Telford, 

 and from the article Canal, in the three principal Encyclopaedias. 



