298 NATURAL HISTORY 



hearers ; not only filling the Lythe with the roar, as if all the 

 beeches were tearing up by the roots ; but turning to the 

 left, they pervaded the vale above Comb Wood Ponds ; and 

 after a pause seemed to take up the crash again, and to 

 extend round Harteley, Hangers, and to die away at last 

 among the coppices and coverts of Ward-le-ham. It has 

 been remarked before that this district is an Anathoth, a 

 place of responses or echoes, and therefore proper for such 

 experiments : we may farther add, that the pauses in echoes, 

 when they cease and yet are taken up again, like the pauses 

 in music, surprise the hearers, and have a fine effect on the 

 imagination. 



The gentleman above mentioned has just fixed a baro- 

 meter in his parlour at Newton Valence. The tube was 

 first filled here (at Selborne) twice with care, when the 

 mercury agreed and stood exactly with my own ; but being 

 filled again twice at Newton, the mercury stood, on account 

 of the great elevation of that house, three-tenths of an inch 

 lower than the barometers at this village, and so continues 

 to do, be the weight of the atmosphere what it may. The 

 plate of the barometer at Newton is figured as low as 27 ; 

 because in stormy weather the mercury there will some- 

 times descend below 28. We have supposed Newton 

 House to stand 200 feet higher than this house : but if the 

 rule holds good, which says that mercury in a barometer 

 sinks one-tenth of an inch for every 100 feet elevation, then 

 the Newton barometer, by standing three tenths lower than 

 that of Selborne, proves that Newton House must be 300 feet 

 higher than that in which I am writing, instead of 200. 



It may not be impertinent to add, that the barometers at 

 Selborne stand three-tenths of an inch lower than the 

 barometers of South Lambeth : whence we may conclude 

 that the former place is about 300 feet higher than the latter; 

 and with good reason, because the streams that rise with us 

 run into the Thames at Weybridge, and so to London. Of 

 course, therefore, there must be lower ground all the way 

 from Selborne to South Lambeth; the distance between 

 which, all the windings and indentings of the streams con- 

 sidered, cannot be less than 100 miles. 



