276 THE NATURAL HISTORY [LETT. 



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 Combwood-ponds ; and after a pause 

 seemed to take up the crash again, and to extend round 

 Harteley-hangers, dying away at last among the coppices and 

 coverts of Wardleham. It has been remarked before that this 

 district is an anatlwth, 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 barometer 

 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 it 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 sometimes descend below 28. We have 

 supposed Newton-house to stand two hundred 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 hundred 

 feet elevation, then the Newton barometer, by standing three- 

 tenths lower than that of Selborne, proves that Newton-house 

 must be three hundred feet higher than that in which I am 

 writing, instead of two hundred. 



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

 Selborne stand three~tenths of an inch below the barometers at 

 South Lambeth ; whence we may conclude that the former 

 place is about three hundred feet higher than the latter ; and 

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

 into the Thames at Wey bridge, 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 wind- 

 ings and indentings of the streams considered, cannot be less 

 than a hundred miles. 



