142 Mr. Bevan's Observations on the Heights of Places, S?c. 



Arbury, neither of which is more than might be expected 

 from the visible inequality of the contiguous land. 



The result of the operations north of Clifton I have not had 

 an opportunity of ascertaining ; but it appears to me that a 

 few more observations by the zenith sector, at other stations, 

 would remove much of the apparent ambiguity at present at- 

 tached to this interesting question. 



Knowing the goodness of the instrument used in the Sur- 

 vey, and the great skill and attention observed by the persons 

 engaged, I have great confidence in the general result of the 

 terrestrial department. I should have been doubly gratified 

 if I could have said as much on the determination of the 

 heights of the stations. 



Availing myself of the levels through a long district of the 

 Grand Junction Canal, I have been at the ti'ouble of levelling 

 from the following stations, viz. 



Wendover Down, 



Kensworth, 



Bowbrick Hill, and 



Arbury Hill, 

 to the nearest point of the said Canal, and thus, by means of 

 the known level of the different parts of the Canal, to obtain 

 the relative heights of the above-mentioned stations. 



And as a comparison will be more readily made from a 

 table of heights expressed in positive numbers, I shall assume 

 the highest point of the summit of said Canal to be 402 feet 

 above the level of the sea at low water spring tides : with 

 this assumption, the heights of the several stations, in feet, 

 above low water mark, will be as follows : 



Wendover Station . . . 861 



Kensworth ditto . . . 809£ 



Bowbrick Hill . . . . '57 H 



Arbury Hill 740£ 



The heights of these stations published in the Philosophical 



Transactions, are as below : in vol. iii. p. 302. 



Wendover 905 



Kensworth 904 



Bowbrick Hill .... 683 

 Arbury Hill 804 



these will average about 78 feet higher than in the table 



above. 



1 have also levelled from the summit of the Regent's Canal, 



to the mouth of the fixed cannon at King's Arbour, or the 



upper end of the base on Hounslow Heath, and upon the 



same data this point will be 90| feet above low water mark. 



In 



