BY A SYSTEM OF WARPING. 89 



from which the tides rush up into rivers or artificial 

 channels, when they are not kept back by too many 

 obstacles, will rise higher at the end of their course than 

 the actual level of the sea itself. The body of moving 

 water entering a wider mouth, if it keep on its course, 

 must heap itself up as its channel becomes narrower, 

 and thus may be made the means of bearing the elements 

 of fertility upwards, and spreading them over surfaces 

 which are already higher in level than the sea from 

 which they come. Of such a heaping up due in part, 

 probably, to this cause I have already mentioned an 

 example in the height to which the tidal waters rise at 

 the Bend on the Eiver Petitcodiac.* 



I found two successful canals in operation, one called 

 Toler s, the other Botsford s, after the enterprising gen 

 tlemen through whose means they were severally exe 

 cuted. The section of these canals showed that the boc: 



o 



rested, as we so often see it elsewhere, upon an older 

 deposit of alluvial clay, so that, when the improvement is 

 completed, it will exhibit a bed of peat between two 

 similar beds of consolidated silt. 



An obstacle which, in operations of this kind, is not 

 always easy to be guarded against, is the tendency of the 

 canals and ditches themselves to become silted up. In 

 regard to the lateral ditches, this can only be pre 

 vented by the occasional expenditure of manual labour 

 in clearing them out ; but the main channels are kept 

 clear by turning a stream of water into them from 

 above. Fortunately, two fresh-water lakes above the 

 head of the Tantamare Marsh afford a body of water 

 which, following the retreating tide, descends with much 

 velocity, and scours out the mud from the main canals. 



The richness of the land thus made does not exceed 

 that of our own warp-lands at home. Some of it, dyked 

 a hundred years ago, and since cut every year for hay, 

 * Vol. i. p. 116. 



