of Inglehorough above the Level of the Sea, 251 



tower, &c.) is of opinion that the walls pointed N.W. and 

 N.E., which would throw its centre further from the station. 



The signals on Farleton Knot, Hutton Roof Moor, and 

 Warton Crag were whitewashed'^ from the base nearly to the 

 top to render them distinguishable at the more elevated sta- 

 tions from the chaos of rocks, &c. of the same hue imme- 

 diately around them. Under a bright sky these signals are so 

 intensely brilliant that they have been seen from distant sta- 

 tions sufficiently distinct for bisection wht?n the hills on which 

 they stood were enveloped in light mist or haze. Marks of 

 this description have, however, their disadvantages, not only 

 fading gradually out of view as the sun advances towards the 

 same quarter of the horizon, which requires in strictness a 

 correction for unequal illumination, but causing on a partially 

 cloudy day numerous tedious interruptions, to the probable 

 injury of the observations. At the Calf, on a bright clear 

 day, none of the signals, owing to their situation to the south- 

 ward, could be satisfactorily identified, with the exception of 

 that on Farleton Knot, recognised from its proximity to the 

 division wall and the precipitous edge of the scars f. 



Whenever the signal on Ingleborough appeared from any 

 other station to have been thrown down, (as was frequently 

 the case until a person was appointed to watch it,) one, and 

 sometimes both sides of the adjacent tower were observed in 

 lieu of it, and the corresponding correction calculated from 

 data of undoubted accuracy. As the flagstaff on Lancaster 

 church tower, which is only nine inches in diameter, could 

 never be seen at Ingleborough sufficiently distinct for bisec- 

 tion, the north-west or south-east, and in some instances both 

 angles of the tower were observed, and the reductions to the 

 flagstaff' computed from a plan of the tower by J. Binns, 

 Esq. J. 



Of the Distances* 



In 1829 and 1830 the requisite angles were measured by 

 my six-inch theodolite on different parts of its divided circle ; 

 but in consequence of the marked differences in the distances 

 derived from the three base lines made use of, the survey was 

 resumed in 1832, with an additional or verification base line 

 (that of the Calf to Ingleborough), and the angles measured, 



♦ When the solution of lime in water is applied hot, it will adhere to 

 the rock and retain its colour several year?. 



f A white signal seen against a clear sky with a low sun in the same 

 quarter, or on a gloomy day, appears of a dull lead colour, and if highly 

 conical will have a figure nearly cylindrical. 



J The sides of the tower are of different lengths, and the flagstaff is not 

 placed at the intersection of the lines drawn (diagonally) from tlie angles. 



2K 2 



