91 
“‘ Calculating the differences of altitude from these observa- 
tions by the tables and formula (Bailey’s) given in Simms’s 
‘ Treatise on Mathematical Instruments,’ we get the follow- 
ing :— 
J. H. 
Feet. Feet. 
Difference of level between (1) & (2)= 6712 | 6673 
Ditto, ditto, (2) &(3)= 3094 | 3-093 
Ditto, ditto, (3) & (4)= 2:197 | 2191 
Ditto, ditto, (4) & (5) = 11-880 | 11-826 
Ditto, ditto, (4) & (6) = 2°192 2°195 
Ditto, ditto, (6) & (7) = 9°841 | 9°720 
Ditto, ditto, (4) & (7) = 11-930 | 11877 
“The numbers given in column J. are from my own cal- 
culations; those in column H. are from the calculations of 
Professor Haughton, who has been kind enough to make them 
for me ‘from the formula in the ‘“‘ Annuaire du Bureau des lon- 
gitudes,” with the exception of the correction for the tempera- 
ture of the air, which is taken from Rudberg’s coefficient 
(viz. 75)” 
«¢ Observations Nos. 1 and 7 were taken at the same spot 
in Oratava, the height of which was estimated at 45 feet above 
the sea. Observation No. 5 was taken in Santa Cruz, at a pro- 
bable height of 50 feet above the sea. 
‘“¢ The total height of the Peak, therefore, will be as fol- 
lows :— 
‘¢ By the observations taken in ascending on May 1, and 
the morning of the 2nd— 
J. (45 + 6712+ 3094 + 2197) = 12,048 feet. 
H. (45 + 6673 + 3093 + 2191) =12,002 _ ,, ce 
By the observations taken in descending on May 2— 
J. (2192 + 9841 + 45) = 12,078 feet. B 
H. (2195 +9720 + 45) =11,960 ,, 
H 2 
