266 Mr. J. Nixon on the Tides in the Bay of Morccambe. 



end. The Keer, which, flowing in its usual channel, passed 

 close by the breakwater at the time of its erection (only a few 

 years ago), soon after receded from it considerably to the 

 north-west; and again altering its course after the rainy au- 

 tumns of 1829 and 1830*, fell into the Grange channel four 

 or five miles above their previous confluence off* Poulton. 

 The height of the north-east or lee side of the breakwater, 

 originally upwards of sixteen feet, is now reduced by the gra- 

 dual deposition of warp to nine feetf. On this account a 

 costly structure for the convenient unshipping of goods de- 

 stined to be forwarded by the Lancaster canal, is now become 

 unserviceable and suffered to go to ruinj. 



In order to find the time, &c, of high water, the east side 

 of the breakwater pole was divided, from its base upwards, 

 to a sufficient height, into feet, and after a few days' observa- 

 tions into half-feet. A board, similarly divided, was nailed per- 

 pendicularly to one of the piles (the nearest to the pole) on the 

 lee side of the breakwater, its upper division being placed ex- 

 actly level with the base of the pole by means of a spirit-level. 

 From the shore (little above the level of the breakwater) these 

 divisions, which were marked and numbered with white paint, 

 were distinctly seen through a 20-inch telescope, and little 

 difficulty occurred in determining in calm weather, and espe- 

 cially at high tides, the nearest minute by the watch when 

 the water appeared level with any division §. With a rough 

 sea dashing over the breakwater it required most vigilant ob- 

 servation to decide when the waves fluctuated as much above 

 as below the mark, or subsided for some moments to the level 

 of it. The observations at neaps, generally more uncertain, 

 were facilitated by the comparative tranquillity of the water by 

 the divided board. The divisions on the pole and board 

 served also to mark the extreme height of the tide above or 

 below the surface of the breakwater. 



When the perpendicular rise and fall of a tide are uniform 

 in rate, half the sum of the times at which it has risen and 



• At the same period a lew sand-bank, called Priest Skear, lying a mile 

 north of the breakwater, gradually assumed the form of an island. Not 

 many years ago it was pasture land connected with the shore, now half a 

 mile distant. 



f This has been explained in Treatises on Harbours. Beneath the warp 

 lies the red marl with ironstone, ranging between Carnforth and Bare. 

 It appears to be the same rock which runs in patches between Ingleton 

 and Kirkby Lonsdale. 



X About thirty years ago the Ulverston canal was rendered nearly use- 

 less by a similar shifting of a branch of the Furness channel. 



§ In general it was most difficult to mark with certainty the time when 

 the sea became level with the bate of the pole. 



