THE 



PHILOSOPHICAL MAGAZINE 



AND 



ANNALS OF PHILOSOPHY. 



[NEW SERIES.] 



JULY 1830. 



I. On the Measurement {by Trigonometry) of the Heights of 

 the jjrincipal Hills of Swaledale, Yorkshire. By John Nixon, 

 Esq.* 



[With a Plate.] 



AVAILING myself last year of the favourable state of the 

 weather about midsummer, I undertook, and within three 

 weeks finished, the Trigonometrical Survey of the Hills of 

 Swaledale, avalleynorth of, and adjoining that of Wensleydale. 

 It was originally intended to have placed signals on the 

 principal hills only (the peculiar features of the dale rendering 

 impracticable the plan adopted in the preceding survey) ; yet 

 the temptation in the course of the operations, of marking for 

 measurement such others of minor note as were situated on 

 our route, could seldom be resisted. The exceptions had at 

 length become so reduced in number, that the deficient signals 

 would have been supplied, and the survey made complete for 

 hills of both descriptions, had not numerous indications of 

 approaching tempestuous weather urged the propriety of 

 commencing the observations without further delay. As an 

 additional motive to dispatch, it was noticed during the pro- 

 gress of the measurements that two of the more distant signals 

 had successively disappeared ; one of which, on West Stones- 

 dale Moor, having been observed from one station only, was 

 totally lost to the survey. The other, on the Nine Standards 

 Hill, had most probably been demolished by a jealous shepherd 

 or keeper, acting under the impression that it had been set up 

 in opposition to the adjacent nine standards or boundary marks 

 between Westmoreland and Yorkshire, whence the fell derives 

 its .name. As the line of demarcation passes in this vicinity 

 through every point on the ridge common to the geological 



* Communicated bv the Author. 

 N. S. Vol. 8. No. 43. July 1830. B troughs 



