1819.J 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



123 



" Description and Drawing of a New Hydraulic Locomotive and Raihcay." 

 By Mr. Daniel Erskine, plumber and gas-fitter, Clerk Street, Edinburgh. 



This locomotive is constructed on a principle altogether different from 

 any other hitherto invented. It resembles the present locomotive only as to 

 the frame-work, while the top resembles a stage coach. The propelling 

 power is water, turning an overshot-wheel, fitted in an air-tight case in the 

 centre of the carriage; the water is supplied by a syphon, fixed to the loco- 

 motive, and dipping into the trough of water after-mentioned. Mr. Erskine 

 showed experimentally that the syphon will do its work, although moving 

 through the water at the rate of 60 miles an hour, and even at greater 

 speed. The syphon is supplied with water from a trough of cast-iron sup- 

 ported over the railway, and having a longitudinal division from end to end 

 open at the top, capable of being heated to prevent t!ie water from freezing 

 in winter. It is to l)e supplied with locks to answer the gradients of the 

 railway. Tne locomotive opens and shuts the locks in travelling along the 

 line, and the surplus water is conduL-ted into a narro^v trough between the 

 two lines of rails, and is allowed to run waste, or used for purposes of irri- 

 gation. 



BELL ROCK LIGHTHOUSE. 



Sir — In answer to your obliging communication as to the time for receiv- 

 ing papers, I beg leave to say that my reply to Sir John Uennie's statement 

 on the subject of the Bell Rock Lighthouse, will occupy a considerable 

 space; and, as I wish to illustrate the subject by some diagrams or drawings, 

 1 cannot be in time for the next number of your excellent Journal. I have 

 been from home, and did not see Sir John Rennie's statement till my return. 

 May I request the favour of your inserting this note in next number? 



I remain, Sir, 



Your most obedient servant, 



Edinburgh, March 14, 1849. Alan Stevenson. 



DEEP DRAINING. 



[The subject of draining connected with agricultural purposes 

 has now become an important branch of the duties of the civil 

 engineer, which induces us to give at length the following valuable 

 paper from the Journal of the Royal Agricultural Society of Eng- 

 land.'] 



On the Failure of Deep Draining on certain strong Clay Subsoils, 

 ii-ith a few Remarks on the Injurious Effect of sinking the Water too 

 far below the Roots of Plants in. very Porous, Alluvial, and Peaty 

 Soils. By William Bullock Webster. 



As I iind the system of very deep draining (4 and .5 feet) on 

 strong clay-subsoils is looked upon by many of our members as a 

 practice altogether new, and one likely to lead to very advanta- 

 geous results, 1 think it of importance to call their attention to 

 facts which have come under my ovvn notice or which I have col- 

 lected from others, .and which will be found strongly in opposition 

 to sucli views. Before I do so, however, as I find that the ])art I 

 have taken in discussions on this question has led to erroneous 

 impressions respecting my opinions on the subject of draining 

 generally, and as I not unfrequently see myself classed among the 

 "shallow drainers," I wish to set myself right with the agricultural 

 public, and to have it distinctly understood that I am not a parti- 

 zan of either faction — am not a deep, a shallow, or a medium 

 drainer; but consider each of the several practices exclusively ad- 

 vocated by various zealous experimentalists proper to be applied 

 in individual cases. It would greatly simplify medical art, could 

 we find one mode of cure adapted to evey constitution and every 

 disease; but though we hear such vaunted, I have no faith in 

 anything professing so much. For deep draining I am strongly an 

 advocate on soils injured by under-water; and on spongy, and 

 some porous soils; but am opposed to the practice of going to a 

 greater depth than 3 feet upon the very strong clay-subsoils, where 

 the injury is not from under-water, but from raiii. To guide me 

 in forming that judgment I have had extensive opportunities of 

 observation, which have led me to the strong conviction that tliis 

 practice is not advisable — first, because (after a time) the water 

 will not find its way to the drains at all; secondly, because if it 

 does so its percolation is usually so slow as not to free the ground 

 from moisture with sufficient readiness to insure the full benefit 

 for agricultural i)urposes; and thirdly, because even when the per- 

 colation is more rapid an effective drainage cannot be accomplislied 

 with the drains placed at intervals so wide as to compensate for 

 the extra expense of sinking them to the increased depth. In 

 cases which have come under my notice where the experiments 



have been tried, I have seen that the land between deep drains at 

 wide intervals was not in so perfect a state for cultivation as that 

 between drains of more moderate depth placed at less distances. 

 The cost of cutting an additional foot deep is very considerable ; 

 in many cases it would double the outlay upon digging. I must 

 observe here that, even among those soils which we class together 

 as strong clays, the conditions arising from local positions and 

 their chemical components are so various, that they cannot all be 

 placed in one category as to the facility or resistance they offer to 

 the percolation of water. Again, in the case of fine rich grass- 

 land on the alluvial, and therefore more pervious soils, I condemn 

 the practice of sinking drains to depths of 4 and 5 feet, as render- 

 ing the ground too dry for the roots of grasses — and exposing 

 them to sufl'er severely in seasons of continued drought. The 

 same objection is applicable, and perhaps in a still stronger de- 

 gree, to moss or peat lands, excepting where they are thickly 

 covered or mixed with some heavier material, such as clay or 

 marl, that has a tendency to retain the moisture. The system of 

 draining deeply in all these instances has not the novelty claimed 

 for it by its modern advocates, but has been tried years since in 

 many parts of England and abandoned because it was found sig- 

 nally to fail. 



Since Elkington, indeed, first drew attention to the full im- 

 portance of draining, a vast number of experiments have been 

 tried upon all the geological formations of this island; and could 

 we but have before us a fair statement of the entire results, we 

 should be furnished, I believe, with sufficient data for our future 

 guidance. 



Almost every system that has in turn been introduced has been 

 attended in some cases with success, and thus has found advo- 

 cates, and had a fictitious importance for a time attached to it: 

 each one has, on the other hand, in some cases failed; nor is it 

 reasonable to expect like results where conditions are totally dif- 

 ferent. 



The prevailing custom until lately was, no doubt, to put in 

 drains much too shallow. I am perfectly aware of the importance 

 of permitting the water to filtrate through a sufficient depth of 

 soil, to leave its valuable properties behind; I know that, under 

 the old system, shallow draining in some cases did harm by carry- 

 ing away too rapidly the soluble parts of the manure. But whilst 

 it is well to avoid the errors of our predecessors it is advisable to 

 exercise caution lest we fall into mistakes of an opposite kind. 

 A system of drainage can only be tested by its results in quantity 

 and quality of produce, and its permanent efficiency only by the 

 observation of these results through a series of years; for in some 

 cases deep draining has appeared to answer, in the first and second 

 years after laying down the tiles, but has subsequently proverl 

 wholly inefficient. Tlie drains upon examination have been dis- 

 covered to be unimpeded, but the water has ceased to find its way 

 down to tliem. 



We have scarcely had time yet since the re-introduction of 

 deep draining upon those soils to which my objections apply, to 

 be able to determine the permanent value even of experiments 

 which are apparently attended with success. Conclusions are 

 drawn much too hastily; and in this, as in other matters, persons 

 of sanguine minds generalise upon very inconclusive data. If 

 water is found to run from pipes laid 4 or 5 feet deep the triumph 

 of deep draining is considered complete; the true test, however, 

 is not in the water thrown off, but in the condition in which the 

 soil is left for agricultural purposes. The real object in draining 

 sliould be to put the land in such a condition that all the rain 

 which falls should do good, or at least do no harm; and this first 

 requisite held primarily in view the problem ne.xt in importance 

 is to effect this with the nicest adjustment of present and future 

 economy. 



Error in new systems is quickly propagated. The person who 

 has reduced theory to practice with real or imaginary success, is 

 proud of bis sagacity and ready to proclaim it: he, on the con- 

 trary, wlio has failed, is by no means anxious to call the attention 

 of the world to his mistakes. In our medical journals may be 

 seen weekly accounts of remarkable cures just completed: the 

 members of the tlierapeutic art do not bring forward with equal 

 eagerness their cases of remarkable homicide. Perhaps, there- 

 fore, while so many successf il experiments in deep drainage are 

 being pressed up^ui tlie public witli entliusiasm, 1 shall not be 

 doing ill service in turning to the other side of the account, and 

 showing that "profit and loss" in tlie drainage-ledger should have 

 entries as well in the debtor as creditor side. I have for some 

 time devoted much attention to the subject, with a mind open to 

 convicti(m and an anxious desire to arrive at truth. I have 

 visited and coiulucted draining operations on almost every geo- 



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