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



At 6 h 30 m a.m. dip 11' 13") T 



7 \ 11 28 | LoW water * 



Mean 11 20j 



Refraction T ^ +57 



Half variation + 10J 



Corrected dip and height of eve 12 28 = 138*0 feet. 

 Tabulated do. 10 25 = 96'3 — 



Errors +2 3 +41*7 — 



The refraction for the dip at noon is unusually great, but 

 that for Black Comb and the lighthouse, is nearly equally in 

 excess. The morning was frosty, and the horizon of the sea, 

 although dull at the first observation for low water, became 

 quite clear at the second. The refraction appears, however, 

 to have been 55% f negative', a probable consequence of a 

 frosty morning succeeding a warm evening, in which case the 

 air would be considerably cooler than the sea. Under si- 

 milar circumstances, Biot has observed the dip at sea to be 

 4 or 5 minutes greater than usual. 



August 24th 1829. 



At 2 h m p.m. (Low water) dip 10' 0\ n 



2 30 9 52f 



Mean 9 5Q\ 



Mean noon refr. Sept. 14, 15, 16 = ?\ +15f 



Corrected dip and height of eye 10 12= 92-3 feet. 



Tabulated do. ... 10 4| = 90*0 — 



Errors +0 7i +2*3 — 



Height of eye at high water 92*6 feet. Lighthouse unob- 

 served. 



August 25th, 1829. 



Errors -0 \\\ -3*3 



