12G 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL 



[APRII,, 



rl.iys of the blue Hm* witli ill suceess many years ago, as Mr. 

 liayles, of Prospect House, near Evesham, in that county, has hail 

 to re-drain land on account of the inefficiency of deep drains. 

 The following is his leter: — 



Prospecl House, near Eresham, Worcestershire, January 13, 1847. 



Dear Sik — I have drained one field over a^ain, owint; to its beinj; loo 

 deep. Tlie draius are fniin 3 to 4 feet ; the land being strong stilf clay 

 iiiidered them useless for surface water; tlie new drains 1 have put in 

 ahout 2 feel, and filled them with broken stones or burnt clay. As to my 

 ijcindy or p<ir-ous soil, I prefer draining deep. Yours, &c., 



\V. B. Webster, Esq., &c., &c. G. Bayles. 



I have seen similar instances of failure in other estates in the 

 same county, in the vale of Evesham. 



T shall add a letter from Mr. Randall, likewise of that neigh- 

 liourhooJ (although it refers to no case of the failui'e of deep 

 drains), as it is founded upon experience. 



Chadbury, near Evesham, February 16, 1847. 



Df.hr Sir — I can give you my opinion of draining clays for surface 

 water in a very f»-w v\or'rls; it is that I would not put in pipes ai a 

 preater depth than 3 feet, nor less than 25 feet. This is lire result of some 

 experience. I fully consider 2j feet sulKcient, Yours, &c. 



W . B. Webster, Esq., &c., &c. C Randall. 



Now if the advantage of deep over shallow draining is so de- 

 cided in uU cases, how is it that those who have tried 3 feet do not 

 altogether abandon 2i and 30 inch drains.'' The advocates for 

 deep draining upon those strong clays upon which such a system 

 has not been in use, say that it only requires that we should try 

 the experiment in order to be convinced of its superiority: where 

 does the proof of superiority commence? If 4. feet is obviously 

 superior to 3 feet, might we not expect that 3 feet would be in an 

 increasing ratio superior to 2 feet.'' We find experienced drainers 

 continuing upon strong clays to vary their depth, being guided 

 therein by other local considerations; but if 5 feet draining is to 

 explode 3 feet draining, the latter ought, long ere this, to have 

 put an end to draining at still less depths. 



I am able to quote a statement from a gentleman in the neigh- 

 bouring county of Herefordshire, whose experience has led him to 

 abandon the practice of laying deep drains in stif}' clays in favour 

 of those of more moderate depth. The practical basis on which 

 his opinion is founded gives it importance. 



Tarington, near Ledbury, Herefordshire, January 28, 1817. 



With reference to your request a^ to my opinion trf the deep drainrng on 

 our s/iff soils, I beg to say, that 1 have had much pi'actical experierrce in 

 drairiHtg such lands, Jormerly at 5 feet deep, very rarely less than 4 ; 

 but Ititteily 2^ and 3 feet. I am fully convinced VWe^i in dense clay lanris 

 30 lo 36 inches is fully as deep as it is pr'ofitable to dram, and that a 

 drain at a greater depth will nut answer the purpose iuteiidid. \\ here 

 Bprin^^s exist the case is of course dtllerent. 1 have drained with the best 

 p|>^siiJle elfect land at 30 inches deep, wher'e I had previously drained at 

 5 feet with only a partial ellect. Y'ouis, &c , C. A. Mason. 



\l . H. Webster, Esq., &;c., &c. 



I think tlie facts I have brought forward are sufficient to sliovv 

 that deep draining w ill not prove successful alike upon all soils 

 and under all conditions. Arguments and opinions unsui)ported 

 by specilic facts are of little comjiarative value; yet when it is 

 shown that what is called the new system of drainage is not new, 

 hut has been tried long ago, great importance must be allowed to 

 attach to its abandonment as evidence of its incfficacy. Elking- 

 ton testifies to the fact of deep drains having been tried as a 

 aieans of removing surface-water from strong clay soils in or 

 before his time. No one could be more an ad\dcate for going 

 deep for springs; but, with reference to trying the same plan for 

 draining clay, he says (see his work, by Johnson, p. 137), " In 

 soils that are so tenacious as to retain water on the surface, this 

 method of draining (deep) has been tried, and found entirely to 

 fail." Indeed, throughout, this work, and all others published up 

 to 1843, condemn going deep in strong clay-subsoils. 



I have myself inspected many of the works executed by Elking- 

 ton, and taken up drains put in by him eighty years ago (he began 

 in net); and my observations, whether upon the state of the 

 lands drained by him where no subsequent system had been tried, 

 or on the condition of tlie drains, went quite to confirm his view. 



I will only further cpiote from old Mr. Tebbet, who made the 

 Duke of Portland's water-meadows (no one will question his sa- 

 gacity and experience); and is the result of his experience to 

 show that the deeper tlie drains the more efficient their action.'' 

 —No! 



Mansfield, Nottingham, January 28, 1847. 



Dkar .Sir — The underdraining 1 have directed upon strong i lay larnl I 

 have uuiie Id variuus vvajs; but ibe l/est way I have uilopicd la to put 



the drains 14 feet apart anrl 2 feet deep. Some clays will draw 18 lo 

 24 feet apart, and 2 to 3 feet deep ; I have seeu a great deal of good dune 

 by critling deep drains for springs 8 and 10 feet deep, and there is much 

 laud lieic that cauuot be made dry unless the springs are removed. 



Yours, &c. T. Tebbet. 



I will not ocupy more space in quoting the opinions of persons 

 who, having had sufficient opportunities of witnessing the effects 

 of various tiepths of drainage, have formed unfavourable conclusions 

 respecting the use of deep drains on strong clay land at wide 

 intervals; though those of old Pearson, the spring -drainer in 

 Essex (see his evidence before the House of Lords); of Smith of 

 Deanston, who first forced upon the public the importance of 

 thorough draining, and did show what could be done in strong 

 land at moderate depths and distances; and of others are before 

 me — these are accessible to the public in other forms. What I 

 have said may, perhaps, be sufficient to excite attention, and set 

 people on their guard against plunging into the expense of a 

 system of drainage which has failed in many instances, and might 

 therefore cause disappointment in many more. 



William Bullock Webster. 

 Hounsdnwn, near Southampton, April 29, 1848. 

 and 48, Charing Cross, London. 



VOLTAIC IGNITION. 



At the Royal Institution, Feb. 16, Mr. Grove delivered a lecture " On 

 Voltaic Ignition." — -Mr. Grove introduced his subject by asserting that the 

 only philosophical idea of heat was that which regards it as a repulsive 

 power — that, with the single exceplion of water and other bodies which as- 

 sumed a crystalline form when about to freeze (a condition which Mr. Grove 

 ascribed to a polar state which these substances then took), all matter ex- 

 panded by heat. Mr. Grove here referred to the experiments of Fresnel and 

 Saigy on discs in vacuo, and the still more recent researches of Prof. Baden 

 Powell on Newton's rings, as showing the repulsive effect of heat, measured 

 by tints of light. This expansion of matter, so caused, can be communi- 

 cated to neighbouring bodies. In the case of heat produced by intense 

 chemical action, the ellect was ascribed to the physical force of a species of 

 molecular friction on the particles acted on. This chemical force is capable 

 of transfer by the voltaic battery, and the calorific force moves with it. Jt 

 was proved by an experiment on a compound wire of silver and platinum, 

 that in proportion to the increase of conducting power, ignition was dimi- 

 nished. Mr. Grove here referred to recent researches of his own to prove 

 that this calorific action was affected by external causes. The same current 

 was sent through two coils of fine platinum wire, one of which was sur- 

 rounded by an atmosphere of air, the other by an atmosphere of hydrogen, 

 when it was found that the wire in air became white-hot, while that in hy- 

 drogen was not heated. This phenomenon Mr. Grove ascribed either to the 

 mobility of the particles of the hydrogen, or to the vibrations moving away 

 from the vibrating surface, or to the state of the surface itself, hydrogen 

 being, as to radiating power, to air what the colour black is to white. That 

 this cooling etfecl does not depend on rarefaction, is proved by the irrteuse 

 beat and light produced by the current in vacuo. Mr. Grove then proceeded 

 to show how the chemical force in the battery acted on masses of matter 

 interposed in the circuit. He exhibited, first, the attraction of gold-leaf 

 terminals, and then explained how liquid masses similarly attracted each 

 other, and noticed a remarkable experiment lately performed by him with 

 M. Gassiot's large battery of 500 cells (Glove's battery): of the two plati- 

 num pules, the positive was placed under water, the negative held over it, 

 when a cone of flame issued from the surface of the water towards the nega- 

 tive pole, on the extremity of which a small globule was formed, which fell 

 ofl' as soon as the current was suspendeil. These facts may serve to explain 

 mure clearly the phenonrena of the voltaic arc. Mr. Grove then exhibited 

 paper on which the strong disruptive etfect of the electric battery had dis- 

 persed metallic wires, and he showed that these explosions had always oc- 

 curred in a line transverse to that of the current, lie inferred that when 

 ignition commenced in the wire its molecules assumed a transverse polar 

 direction. He stated that when platinum is ignited by the current under 

 circumstances which admit of the effects being accurately noticed, it con- 

 tracts, swells, and breaks, and that a leail wire, similarly acted on, becomes 

 divided by a series of transverse facets. In conclusion, Mr. Grove adverted 

 to recent endeavours to obtain voltaic light for practical purposes. After 

 noticing tliat no greater power of proilucirrg light had been olitained since 

 the inveiilion of bis nilnc acid battery, nine years ago, Mr. Grove stated that 

 recent calculations led hirri to believe that for some purposes, such as the 

 illumination of lighthouses, especially where an intermittent light was 

 wanted, and of the inteiior of large buildings, it might possibly be adopted 

 at no very remote period. He mentioned that the light of 1,440 candles 

 might he oht.iined at about 4»'. per hour ; but this concentrated light was nut 

 applicable tor sreets. The whole subject, however, was beset by many me- 

 chanical difficulties. 



