702 eeport — 1878. 



phleurn nodosum, excellent hay for hunting horses, and lets for £6 to £8 an acre. I 

 have dug up and examined the soils of the three qualities of meadow, and failed to 

 discover any difference. The difference in the values of the meadows results from a 

 difference of the levels of the lands. The Timothy grass (such good horse hay) 

 meadow lands are 9 inches to 15 inches higher than the others, and are consequently 

 above water a month earlier in spring, when they shine forth beautiful bright green 

 islands. The sedgy, weedy meadows are the lowest by some inches, and are satu- 

 rated longer tban the others. The kindness of the soil of these is evinced in many 

 places by the following interesting fact : on examining the surfaces closely numerous 

 plants of clovers and some fine species of grass are to be seen, healthy, but small and 

 distant. Of course if these lands were freed from saturation during spring, summer, 

 and autumn, the clover and fine species of grass would flourish and extend in a 

 material degree, and in a few years these meadows would become much increased 

 in value. 



The aggregate amount of injury to the crops from small floods in thirty years far 

 exceeds the amount of damages that have actually occurred from the one great 

 autumn flood that has occurred in that period. 



The quantity of water flowing off in the river at Killaloe from a rain basin of 

 4,000 square miles, 2,560,000 acres, in all those small floods is under 300,000 cubic 

 feet per minute. The present river channel is fully broad and deep enough to carry 

 off that quantity and more at a moderate velocity. The only obstructions are the 

 weir mounds. While all the low land for 120 miles lies scarcely flooded, but 

 steeped in water, the weir "mounds, with a fall of several feet at each, but without 

 any sluice or flood-gate, act as permanent artificial barriers to the flow of the river. 

 Fifty lineal feet of open sluice in each weir would relieve all the low land in the 

 Shannon valley from saturation. 



The Great Autumn Floods. — One great autumn flood has occurred in the Shan- 

 non during the last thirty years. It destroyed the whole of the crops on 16,300 acres, 

 and injured 3,000 acres more. It began to go out on the ground at Portumna on 

 August 13, 1861, and rose 1 foot 3 inches in five days. It remained at that height 

 for five days more, when it began to fall. The very lowest lots of land were covered 

 with water 1 foot 9 inches deep. The large areas of meadow were covered merely 



1 foot 6 inches deep. The flood began to fall on August 24, and continued to fall at 

 the average rate of an inch a day till September 9, then there was no water on the 

 meadows, and so it remained till September 23, fifteen days; but the water in the 

 river and the drains was even with the surface of the land. In working at the hay, 

 men's feet sank into the ground. The muddy water rose after them. The hay lay 

 there under the owners' eyes rotting, scarcely covered, but wholly saturated, for 

 fourteen days. There was during all that time a fall of 3 feet over the Killaloe 



' weir mound. 



It is important to note well here two things — how slowly the flood rose on the 

 land, merely 22 inches in six days, or 3§ inches average in twenty-four hours; 

 second, what a small depth of flood water there was on the land, viz., 19 inches 

 depth of water for five days, 13 inches depth for ten days, 10 inches depth of water 

 for twelve days. Saturation merely then for fifteen days more up till September 24, 

 yet it rotted the whole crop ; but it must be easy to prevent such small inundation. 



Another very important fact to note ; there is no obstruction whatever in the 

 Shannon at or near Portumna to prevent the free flow of its flood waters into Lou^h 

 Derg, which is a wide and deep lake of 30,000 acres, 22£ miles long. This wide 

 deep water, having no appreciable fall in the surface, goes to within 800 feet of the 

 great weir mound at Killaloe. This channel for 800 feet length is 470 feet wide, 

 with 8 feet depth of running water, and an inclination of 1£ foot per mile down 

 to the weir. Over the weir mound there is a sudden fall of the water of 2 feet 



2 inches. 



This diagram section annexed represents accurately the relative levels and incli- 

 nations of that flood above, at, and below Killaloe weir. It is drawn from levels 

 taken by myself there with a spirit level in August, 1861, when that flood was at 

 its highest. 



There was, as measured by me in the height of that greatest of autumn floods, 

 on August 21, 1861, a cataract, a clear fall of 2 feet 2 inches over the weir. The 



