704 PHILOSOPHICAL TKANSACTIOIiS. [aNNO 1775. 



a tour through the Highlands of Scotland in the summer of the year 1773, 

 taking notice of the principal hills in England which lay in his route, either in 

 his going or in his return. It appeared from his observations, that scarcely any 

 hill was so well adapted to the purpose as our sanguine hopes had led us to expect; 

 for either they were not high enough, or not sufficiently detached from other 

 hills, or their greatest length fell in a wrong direction, too near the meridian, 

 instead of lying nearly east and west, which is a (;ircumstance requisite to make 

 a hill of a given height afford the greatest effect of attraction. In particular, 

 the hills on the confines of Yorkshire and Lancashire, mentioned in the fore- 

 going proposal, were found not to answer the description that had been given 

 of them. Fortunately however Perthshire afforded a remarkable hill, nearly in 

 the centre of Scotland, of sufficient height, tolerably detached from other hills, 

 and considerably larger from east to west than from north to south, called by the 

 people of the low country Maiden-pap, but by the neighbouring inhabitants, 

 Schehallien; which, I have since been informed, signifies in the Erse language, 

 constant storm; a name well adapted to the appearance which it so frequently 

 exhibits to those who live near it, by the clouds and mists which usually crown 

 its summit. It had also the advantage, by its steepness, of having but a small 

 base from north to south ; which circumstance, at the same time that it increases 

 the effect of attraction, brings the two stations on the north and south sides of 

 the hill, at which the sum of the two contrary attractions is to be found by the 

 experiment, nearer together; so that the necessary allowance of the number of 

 seconds, for the difference of latitude due to the measured horizontal distance of 

 the two stations, in the direction of the meridian, would be very small, and con- 

 sequently not subject to sensible error from any probable uncertainty of the 

 length of a degree of latitude in this parallel. For these reasons the mountain 

 Schehallien was chosen, in preference to all others, for the scene of the intended 

 operations, and it was concluded to make the experiment in the summer of the 

 year 1774. 



It was foreseen that this experiment would be attended with considerable ex 

 pence, and such as might easily have exceeded the common funds of the r. s., 

 without some extraordinary assistance. The bounty of his majesty, our patron, 

 happily removed this difficulty. At the humble request of the Society, his 

 majesty had been graciously pleased to grant a very ample sum to their disposal, 

 for defraying the expences of the observations of the late transit of Venus in 

 1769, as his majesty had before done with respect to the former transit of Venus 

 in 1761. Out of this benefaction, after all expences had been paid, there was 

 a considerable remainder; and, the Society humbly requesting to know his ma- 

 jesty's pleasure about the disposal of it, he was graciously pleased to direct them, 

 to lay it out in such manner as they thought proper, and was most agreeable to 



