HEATHER - BURNING 413 



Draining. 



Close observers of " Grouse Disease " have always held the idea that the 

 mortality has been in some way connected with the wet, undrained portions 

 of the moor. Scientific investigation shows that there is probably a good deal 

 of truth in this view. The Strongyle larvae have been shown to pass the free- 

 living portions of their lives in damp surroundings. Even in frozen water 

 they appear to live for an indefinite period, whereas complete drought may 

 kill them in a very short time. 



Without putting drainage forward as an absolute specific against disease, it 

 can be urged with confidence that a well-drained moor is less liable to dangerous 

 infection of nematode worms than a moor with stagnant pools and great stretches 

 of flow ground. Draining should be done with care and on a well-considered 

 plan. Nothing is more common than to see the water carefully drained from 

 the top of a hill-face descending only to flood a much larger acreage below, 

 owing to there being insufficient drainage arrangements for carrying off" the 

 surface water thus collected. 



It will generally be found advisable to employ a professional sheep-drainer 

 and allow him to work by contract at a fixed price per chain. The specifications 

 must ensure that the drain is clear cut, at least the breadth of a spade at the 

 bottom, that the sides are at a slope of not more than one in two, and that 

 the turf dug out is thrown away not less than 6 feet from the drain. Shallow 

 drains made in this way reduce the danger to the young Grouse, and are 

 also less liable to choke and flood the moor. Drains should be made on the 

 herring-bone pattern, and begin with wide arms high up the hill-face to catch the 

 surface water. Special care must be taken that the central drains are sufficiently 

 large to allow the water collected to run oflF easily into a main burn. The ground 

 that it is desirable to drain is not the flat sodden bog or sour flow land, but the 

 ground on which the fog or moss has only recently begun to choke the heather. 



Draining, when undertaken, should be thorough. It is better to confine 

 the area of work and watch results, with an occasional clearing of the drains, 

 than to spread the work over a great extent of country where little immediate 

 result is seen, no attention is paid to upkeep, and the lie of the drains is soon 

 lost. On most moors money would be well expended in draining, for not only 

 would the risk of infection be thereby lessened but the total yield of heather would 

 be increased. The supply of grit which drain-making is apt to expose is not a 

 trifling consideration to the general health of a moor, as will be seen in chapter v. 



