76 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[March, 



feel, which nrccEsarily produced a corresponding increase in Ihe full or in- 

 cliiialion in Ihe current, and thus pave it increased velocity and power lo 

 scour away and reiiove Ihe obblacles in the bed of the river, and to dis- 

 charge a greater quaniity of water in the same lime, as well as a longer 

 period for dibcharjiing ii, to the great benefit of the country drained by it. 

 The tidal waters, njori (jver, beiii;; freed from tiie shifting sands and circuit- 

 ous course of Ihe old chaiiiiei. and being confined in one mass in tlie new 

 direct channel, acted with greater eliVtt; finding Iheir way upwards, and 

 becoming uniltd with the freth waters in enlarging and deepening the 

 channel above, they kept it open to its jjroper dimensions, and thus boili 

 the diainage and the navigation deri>ed benefit from this great woik. The 

 improvement was carried still further, in adding one-lhiid to the dimen- 

 sions of the rut, parlicidai ly at Ihe upper end ; by this means an additional 

 fall ol about 2 fiet (• inches was obtained, making a total increase of about 

 7 leet G inches in Ihe fall of the current at the upper end. 1 he eflett of 

 these improvements has been to increase greatly the produce and value of 

 upwards of 300,000 acies of land drained by the Ouse, which otherwise 

 could not have been cultivated. 1 he measure, like almost all other great 

 impiovemenis. encountered great opposition at (he time, and in order lo 

 tranquijite the fears of some and satisfy the prejudices of others, varitms 

 iniuor interior works wen- provided, such as Icjcks and weirs, fur penning 

 up tie water, most of which, but for existing prejudices, it would have 

 been belter to have dispensed with, and to have removed Denver sluice, 

 rai^iu^ the banks on the various rivers above, so as to have restoied them 

 lo their natural slate, and thus by admitting a greater quantity of tidal 

 water, to have scoured out their channels, and thereby have enabled them 

 lo carry olfthe drainage waters more elfeclually. 



A similar operation was executed by Telford and Rennie, on Ihe river 

 Nene, in 1829, at the Nene outfall, which commences about five miles be- 

 low AVisbeach, and terminaies at bkate's Corner, a length of nearly 5 miles, 

 where it joins the great estuaiv of the \l ash. 'I'he beneficial eil'ects of this 

 work have been very extraordinary ; the low-water mark has been lowered 

 10 feet G inches, and a district ol above ]IjO,OUO acres has been completely 

 drained and brought into cultivation, which formerly for the greater part 

 of the year was lillle belter than a stagnant marsh ; the navigation has 

 been so much improved, that the tide rises 1-1 leet atA\ isbeach,and vessels 

 of 200 tons are now enabled to come up lo that town, where previously the 

 ri\er was only navigable for small sloops; and at Sutton Bridge, 8 miles 

 lov\er down, Tcssels of above COO tons can arrive where formerly there was 

 only water for vessels of 200 tons. 



The river Kene having been thus improved, so as to enable it to carry 

 cfT the tidal and fresh waters, an extensive plan for the interior drainage 

 was desigiied and tarried into effect by Telford, in Ui30. It consisted of 

 one main drain of proper dimensions, with two subsidiary drains of smaller 

 capacity, extending above 20 miles, as far as Thorney, to bring down and 

 discharge all the water from the low fenland districts into the upper end 

 of Ihe new outfall, by means of a capacious new sluice with sell-acting 

 gales, which continues to discharge the waterfrom Ihe drains intolheNene, 

 60 long as Ihe level of the water in the drain is higher than that ol the 

 river ; but whenever the water in the river is higher, the sluice-gates close 

 and prevent the river water from entering. This plan of Telford's resem- 

 bled one jircviously proposed by Rennie for the same object, but which 

 was U|ion a more extensive scale, and was accompanied by the important 

 addition of catch-water drains. 



In 180G, Kennie projiosed and carried into effect a complete system of 

 drainage, for an extensive district of feii-land, called the East, AV est, and 

 At iklinore Kens, bordering upon the river A\ itbam, into which they drained, 

 about 10 Utiles abo\e lioston. IJeunie at once ptrceivefl the defects of the 

 M itham as a means of drainage and navigation, and decided that until the 

 n\er was improved by shortening its course and increasing the capacity of 

 its channel, the complete drainage could not be eflecled. This plan he 

 proposed, but Ihe opposition was so strenuous that he was obliged to aban- 

 don It, and lo carry bis main drains into the river below the town of Bos- 

 ton : he divided the drains into two classes; one set he technically termed 

 catch-waler drains, which running along the base of the hills surrounding 

 the low lands, intercepted all the high land waters, which, descending with 

 great velocity, would soon have overwhelmed the low lands, in addition lo 

 the water falling upon them according to the extent of their surfaces. 

 Ihesehigh land waters were conducted by the catch-water drains into a 

 main drain, which discharged the waters, by a self-acting sluice, into the 

 M itham immediately below Boston ; the low land waters thus freed from 

 the high laud waters, were conducted by separate drains into another main 

 drain at Hobhole, about 3 miles lov\er down the M'itham, where there was 

 niore fall. By this means IjolIi classes of waters were discharged without 

 interfering with each other; means were also seemed of discharging all 

 Ihe water by the lower drain at Hobhole, in case it should be found neces- 

 sary, which iillimalely happened, and it was made of additional capacily 

 for that object. 1 he district was thus completely drained, and Iroiii a 

 stagnant marsh was convened into coru-lielos. 



'Ihe \l itham being left to itself, became silled up in 1827, as had been 

 foreseen by liennie, and the neap tides scarcely flowed above 3 to 4 feet at 

 Boston. The channel was then improved as rectiniUitndtd by him, and the 

 river is now iu such a slate that vessels diawing 12 and 14 feet arrive at 

 Boston, and lhe^^hole country drained by the Mithaui has been propor- 

 tionably benefited. 



lie proposed a similar plan for the iniproveroent of the Great Bedford 

 level in Ihll, the cost of which he estimated at l,188,lfc9/. ; but unlorlu- 

 Ealelj for that district it has never >el been carried into ellect, although it 



would have amply repaid the outlay. The origin of Ihe above system, it 

 is believed, is due lo Kennie, although it is said by some that ;he Kunians 

 eniplojed catch-water drains, and the Caer-dike is (pioled as an example : 

 it is, however, by no means clear whether it was not merely a navigable 

 canal lo connect the Neiie and the M'itham ; at all events, the system, if 

 ever it existed, had long been abandoned, and the revival, at least in mo- 

 dern tiroes, is due to him. He also proposed the drainage of the Hatfield 

 Chase and Ancholme districts, and liomney Warsh,* Holdernesse, and 

 other districts upon similar principles, vtbere drainage had been tried and 

 had only partially succeeded. 



After mature consideration and experience, it appears that the safest and 

 most certain principles of drainage and navigation are: — The improvement 

 of the channels and outfalls of Ihe rivers, as far as may be practicable, for 

 the free admission and discharge of the tidal and fresh w aters ; w ith in- 

 terior drains, well laid out, of proper proportion and capacily for the low 

 land, and catch-waler drains fur the high land waters ; and according to 

 circumstances, the drainage and navigation may be combined or kept sepa- 

 rate. 



Steam Druiiiage. — AVhere natural drainage could not be eflecled, or was 

 only imperfectly applied, recourse was had to windmills and scoop wheels, 

 as still used in Holland; these were always adopted until lh::0, when 

 A\ alt's steam engine was successfully applied by Heunie to work a large 

 scoop-wheel, for draining Boltisham Ten, near Ely. Subsequently this 

 valuable sjstem has been applied and extended by Glynn, Eield, and 

 others, to the great iniproveroent of fen-lands, by draining the wati r lower 

 beneath the surface than could be done by windmills, which are now 

 almost generally supeiseded by steam engines; the latter can be used 

 wlien recpiired, whereas the windmills can only be emploved when iheie is 

 wind ; and it frequently happens that calms prevail during rainy weather, 

 at the very time when the mills are most wanted. 



A\ hilst carrying out the improvements of the outfalls and nu ulhs of 

 rivers, it often occurs that large tracts of sand and mud niaj be converted into 

 fine arable land, fit for agricultural purposes, by accelerating Ihe uatural 

 accumulation of warp, or alluvial matter, held in mechanical suspension by 

 Ihe water, and which, from Ihe absence of proper measures, is otherwise 

 carried away without producing any benefit. The works few this object 

 and for imiJioving the drainage and navigation, if properly conducted, con- 

 sist generally in regulating and confining the channels of the rivers, through 

 Ihe sands below high-water mark, to one channel, for both the hood and 

 ebb waters, and accelerating gradually Ihe accumulation of alluvial de- 

 posit, by jetties and other light works adjacent to them ; in pruportiou as 

 the deposit accumulates, the works are raised until vegetation appears, 

 which generally takes place about the level of high water of neap tides, and 

 then the land is embanked from the sea. The system of warping or artifi- 

 cially soiling bad laud where Ihe levels will permit, has been practised for 

 many years along the Trent, Ouse, and H umber, with considerable success. 

 The operation consists in aduiiltmg, through sluices and canals made for 

 the purpose, the water charged with alluvial U)atter in suspeusiou, to the 

 lands to be warped, which are surrounded with embankments, and after 

 having deposited the alluvial matter the waters are conducted avvaj again 

 to Ihe river ; this process is repeated at intervals until the lands have been 

 sufiiciently warped, and thus lands which, in some cases, are situated 

 several miles from the rivers, and were comparatively worth litlle, have 

 become extremely valuable. If these operations be judiciously conducted, 

 the outfalls of Ihe rivers, and the harbours and draina;.,e and navigation 

 depending on them, may be greatly improved, and the land gamed during 

 the operation will, in many cases, amply repay the cost of draining it. in 

 Holland, and other countries, there is a great field open : much depends 

 upon the situation and other local ciicumstances ; considerable joeigmeut 

 and skill is required in selecting the districts, and in properly applv lug the 

 system, but its consequences are so important that it is well worthy of the 

 attention of engineers. A scheme of-this kind upon an extensive scale is 

 about being carried into effect at the mouth of Ihe Ouse and Nene, where 

 above 30, OUO acres of land VTiU be gained, and great improvement will be 

 effected iii the drainage and navigation of the extensive districts drained 

 by the Ouse ana Nene. Tlie same principle is applicable, in some cases, 

 for converting shoals into effective breakwaters. 



Waciunery and Manufactures. 



The improvement and extension of machinery and manufactures by new 

 inventions and api>lications have been immense since the time of Snieatou. 

 Previous lo that period wood was almost exclusively Used in the' construc- 

 tion of machinery. Desaguliers, Leupold, Gravesande, and other wruers, 

 have given descriptions of the best specimens of mills and machinery iu use 

 a century ago, but they were very defective, both in proportion and con- 

 struction, when compared with modern machinery for similar purposes. 

 Ihe introduction of cast iron by Smeaton, in 1754, was a gieat step lu ad- 

 vance. He began by employing cast iron for the axis of one of his earliest 

 wiuduiills, in 17i4 ; then lu 1700, lor the shaft of a water-wheel, and the 

 main-wheel attached to it, for boring cannon at Canon ; cast iron aiter- 



* The tliflitutties bere ore peculiar, in consequence of the coast being tiurromided vvitli 

 a broad tjelt of loose &liiij(jle, vvhicli renders it necessary to carry tire draiiiiige water 

 lliroiigtl llie Ee=v baiilis by close tuhiiels, vMlli valves at llleu outer extremities, so as lo be 

 (orced open by the Iijaraullc pressure ol the water. Dynichurch wlU, or sea-I-aek, liere is 

 well vvoittiy ol teniaik : it was loimed iu the Dutch nmniier b> stakes vvallitci tegether, 

 and conslaully required rei)Utr ; it has since been laced wilh stone paving, at an inclina- 

 tion 01 about to 1, vvnich slaiius v\cU, Quel rteialA cUectuully the licary seas to which It 

 U exposed. 



