the Trigonometrical Station on Rumbles, Moor^ Yorkshire. 257 



cipitous valley with mountains of superior altitude beyond. 

 Great Whernside, for instance, is 719 feet higher and scarcely 

 ten miles N. W. of Symon Seat ; yet as the latter is on the 

 excessively steep termination of Barden Fell, with the inter- 

 vening deep valley of TroUer's Gill, the plumb-line appears to 

 have been drawn towards the south-east. To be brief, such 

 of your readers as may not have access to Greenough's or 

 Greenwood's map must defer their critique until I am able to 

 furnish you with a sketch of Wharfdale. It is necessary to 

 remark that the errors of pointure, the effect of unequal at- 

 traction and other irregularities, may in some instances affect 

 the refraction in the same way, and that in others they may 

 wholly or partially compensate each other. 



In determining the value of a degree of the meridian in this 

 country, will not the amplitude of the celestial arc have been 

 estimated in excess, and the length of the degree consequently 

 under-rated, by erecting the zenith-sector at Burleigh Moor, 

 and at Dunnose, — the excess of matter being to the south at 

 the former place, and to the north at the latter? 



(I. H.) Inglebormigh Hill. 237i'i feet {grou?ici). 



The base is of limestone and nearly 20 miles in circum- 

 ference. The summit is of grit, remarkably flat, and about 

 400 yax'ds across. It is placed quite to the west of the centre 

 of its huge base. (See Professor Playfair's comment on the 

 Huttonian theory.) 



1822. ^ Therm. Bar. 



June 13th l.'J*' to 18" 57 to 66 (28*050 to 27-950) 16 obs. 



li 13 to 18 51 to 61 11 



17 10 to 16 57 to 61 9 



Feet. Feet. 

 P.G. Wall. 5' 15" lobs. yV E. 91-1 " 98-2 



R. L. 8 57 3 2V S.E. 576-4 578-6 



W. S. Wall. 12 4 2 yVF-N.E. 67-0 68-1 



+ G.W. Rock. 14 2 5 5'^ E. 67-2 64-6 



*^* —P.M. 18 13 2 ^V S. by E. 540-5 545'6 



+ S. S. Rock. 19 48 1 ^'^ E.S.E. 790-1 783-6 



(G. W.) Great Whernside. Rock 2^10 feet. 

 Limestone with grit superposed, steep to the W.S. & S.E. 



1822. April 15th, 10'' to 17''. Therm. 43 to 50. 29 obs. 



(At Kettlewell, 1615 feet lower, tlie temperature was steadily 



7i° higher.) 



•<»* Between Pendlehill and InglehorouKh the country is almost entirely 

 champaign. The observation on the I3th was 24' 21"; on the 1 Ith 

 24' 21^". Four miles vorlk of Ingleborough is the huge mass of" Whern- 

 side, exactly 40 feet liiglier. 



Vol. 61. No. SOO. April 1823. K k April 



