84 



THE FARMER'S MAGAZINE. 



their confluence the channels of our rivers must have 

 a uniform inclination, so far as possible, in order to ob- 

 tain the desired velocity ; thereby securing the quickest 

 removal of the water with a minimum depth, together 

 with the proper drainage of the adjacent lands on both 

 sides. Were it possible to turn the water of the River 

 Thames into the bed of the Tay, the Spey, or the Find- 

 horn, where these rivers are crossed by the great trunk- 

 railway of the North, we should then not only have a 

 clear crystal stream, but one so shallow, that any High- 

 land girl herding her father's cows could easily wade it 

 without wetting her petticoats. 



The facts of the case are thus as plain as 

 the letters of the alphabet. It is the velo- 

 city, the rapid and continuous unretarded flow 

 in our rivers, that can effectually drain the country 

 of its superfluous water — that can preserve tlie atmo- 

 sphere in its normal purity — that can secure health for 

 the inhabitants of our low-lying districts, and that will 

 permit the soil to be properly cultivated so as to yield 

 sound health-giving produce for man and beast. On 

 the contrary, it is the retardation and stagnation of water 

 in our rivers by the ninety-and-nine obstructions exem- 

 plified in every valley, that floods the land — that pro- 

 duces pestilential gases, an unhealthy atmosphere, coarse 

 herbage, disease in man and beast, and little profits on 

 capital invested in what might be the best-paying land 

 in the kingdom. 



It is impossible, therefore, to parley the matter any 

 longer with mill-dams, water-wheels, et hoc genus 

 ovme. Every obstruction of this kind must be removed 

 from our river valleys. Not a vestige of mill-dams and 

 water-wheels can be left behind, in the vast majority of 

 cases, to tell where once they were. 



No doubt some landowners and millers may feel a 

 little reluctance to subscribe so sweeping a proposition. 

 Many a set-ofF has been advanced in favour of "the 

 mill " and " the mill-dam." They are old aff"airs, and 

 sacred in the memory of the past. Their erection cost 

 our forefathers much engineering skill and no little out- 

 lay of capital. To landowners they have long been a 

 very special source of rent, while the miller continues to 

 be one of the most respected guests at an audit dinner. 

 All this and a great deal more must in justice be ac- 

 cepted in favour of things as they are and have been. 



But granting the utmost that can be pleaded on this 

 side of the question, systems grow olcl and give place to 

 others, just as do landowners and millers, and the con- 

 version of our rivers into canals and mill-dams must in 

 like manner give place to railroads, steam power, and 

 the general progress of things. Heavy rains and all 

 superfluous water are now, through the instrumentality 

 of a thorough system of drainage, removed from "up- 

 lands " in the shortest possible period of time, and 

 thrown into our large valleys, and we must consequently 

 proceed to drain them on similarly sound hydraulic 

 principles. 



Before following up the progressive steps of so im- 

 portant an inquiry, let us dispose of one of the offsets 

 above referred to, that deserves a special notice, viz., "a 

 mala drain on each side of the mill-dam, with an outfall 



immediately below the mill for the drainage of the ad- 

 jacent grounds." 



We have had occasion to examine professionally, as an 

 engineer, many propositions of this kind, but never yet 

 found a single case practically tenable. We have met 

 with many cases where advantage was taken of the in- 

 clination of the river to start successfully a powerful 

 water-wheel, but in such examples there was no dam- 

 ming back of the water, and hence no mill-dam in the 

 river to retard the removal of those heavy floods that 

 inundate our valleys. The conversion of a river or 

 maintrunk drain into a standing lake, raising the water 

 many feet above its normal level, is in itself diametri- 

 cally opposed to drainage, to say nothing of the noxious 

 decomposition of animal and vegetable matter in all 

 stagnant water of this kind, and the pestilential malaria 

 that is consequently continually given off from its sur- 

 face, polluting- the atmosphere. 



To this side-drainage system there are other objections 

 to those above, of which the following may be given as 

 examples : A side drain seldom or ever intercepts the 

 water that escapes from the dam so as to prevent it 

 from rising by capillary action or otherwise somewhere 

 in the adjoining lands. There may be examples of per- 

 fect interception and drainage, but we ourselves have 

 never met with one. Again, in time of heavy floods, 

 when side-drains are most required, they are worse 

 than useless, owing to the state of their outfalls imme- 

 diately below the mill. While in ninety-nine cases out 

 of every hundred our rivers require to be deepened at 

 those very outfalls, and this cannot be done at present, 

 owing to the tailing back of the water of the mill-dam 

 below. 



The proper river- drainage of the country involves 

 these and many other important engineering questions. 

 Each example has its own peculiarities, present and 

 future, as to details, whether we view it merely as a 

 trunk-drain, or in a more extended sense as to expense, 

 produce, and profit to landlords and tenants. 



Examined from anenginoering point of view, as a trunk 

 drain only, it would not take a very large channel, if it 

 could be cut in a straight line, to carry off all the water 

 that now flows in any of our rivers. Towards its con- 

 fluence with the sea, if a tidal river, considerable bank- 

 ing might be necessary, to prevent flooding at high 

 tides ; but in all cases of this kind, as it is the extremes 

 for which provision has to be made, if the highest 

 tide-lands are attended to, engineering' difficulties dis- 

 appear. 



A straight river has many things in its favour. It is more 

 easily made in the outset, and kept in repair afterwards, 

 while it will carry off" the most water, other conditions 

 being equal, and occupy the least area of ground. 



Where the valley on both sides of the river belongs to 

 one landowner, and where there are many sharp bends, 

 giving rise to eddies, and consequently to retardation of 

 velocity, the landowner will have little difficulty in de- 

 termining what course to pursue ; and often, where the 

 river winds about between two different estates, the two 

 proprietors may profitably adopt the maxim of " take 

 and give," By so doing, they will not only economies 



