ON  THE  PEAK  OF  TENEEIEFE. 
623 
was  corrected  further  for  the  variation  of  barometric  height  with  the  hour  of  the 
day,  as  indicated  by  the  observations  already  given,  and  arranged  in  the  following 
approximate  Table,  where  the  sign  shows  the  manner  in  which  the  tabular  feet  are  to 
be  apphed  as  corrections  to  the  barometrical,  to  give  the  true  altitude ; the  arguments 
along  the  top  of  the  Table  being  the  approximate  height  of  the  station,  and  on  the  side, 
the  hour  of  the  day,  apparent  solar  time. 
Correction  for  Barometrical  Altitudes  for  hour  of  day, 
and  approximate  height. 
Approximate  altitude  of  station  in  feet. 
Approxi- 
mate solar 
time  of  ob- 
servation. 
10,000. 
8000. 
6000. 
4000. 
2000. 
h 
6 A.M. 
+ 15 
-1-12 
+ 8 
A 5 
+ 2 
7 A.M. 
+ 5 
+ 4 
+ 2 
+ 2 
+ 1 
8 A.M, 
0 
0 
0 
0 
0 
9 A.M. 
- 20 
— 15 
-10 
- 6 
— 3 
10  A.M. 
- 70 
— 52 
-35 
-23 
— 12 
11  A.M. 
— 100 
-75 
-50 
— 33 
-17 
0 P.M. 
-100 
-75 
— 50 
-33 
-17 
1 P.M. 
-115 
-80 
-60 
— 40 
— 20 
2 P.M. 
- 95 
-72 
-50 
-33 
-17 
3 P.M. 
- 60 
-45 
-30 
-20 
-10 
4 P.M. 
- 30 
— 22 
-15 
-10 
- 5 
5 P.M. 
— 10 
- 8 
— 5 
— 4 
— 2 
! 6 P.M. 
— 5 
— 4 
- 2 
- 2 
- 1 
For  the  height  of  the  Peak,  measured  during  an  ascent  on  September  8,  and  resting 
on  live  hourly  observations  from  11  a.m.  to  4 p.m.,  a special  method  was  employed.  The 
barometer  was  simultaneously  observed  at  Alta  Vista,  and  gave  the  height  of  that  sta- 
tion, for  the  interval,  too  high  by  35  feet,  this  quantity  being  compounded  of  the  daily 
and  the  hourly  correction.  Then  increasing  this  quantity  to  41  feet,  for  the  proportion 
between  the  height  of  the  Alta  Vista  and  the  sympiesometer  station  in  a cleft  on  the 
western  side  of  the  crater  at  the  summit  of  the  Peak,  and  levelling  thence  to  the  culmi- 
nating point  of  the  whole,  a part  of  the  north-eastern  wall  of  the  crater,  we  have  12,198 
for  the  height  of  the  Peak  of  Teneriffe. 
A series  of  heights  of  notable  points  will  then  run  as  follows : — 
Culminating  point  of  the  Peak 
Base  of  small  cone  on  the  eastern  side,  or  llambleta 
Narix 
Ice  cavern 
Alta  Vista 
Estancia  de  los  Ingleses 
Base  of  steepest  portion  of  great  cone  of  eruption,  where  it 
adjoins  Montana  Blanco 8,930 
Engl.  feet. 
12,198 
11,745 
11,600(1) 
11,044 
10,702 
9,710 
