ON  THE  PEAK  OF  TENEEIFFE. 
521 
For  the  height  of  Guajara,  the  mean  of  its  series,  or  8903  feet,  may  be  adopted. 
For  the  height  of  Alta  Vista,  the  mean  of  the  whole  series  is  10,691  feet ; but  seeing 
that  decidedly  exceptional  weather  began  on  September  14,  and  that  the  mean  of  the 
days  from  August  21  to  September  13  is  10712,  the  mean  of  the  two  determinations 
may  probably  be  the  closest  approximation  to  the  real  height,  which  therefore  comes 
out  10,702  feet. 
(5*.)  Difference  of  Meteorological  Elements  between  the  Yacht  in  Santa  Cruz  Roads  and 
the  Town  of  Orotava. 
The  mountain  observations  ha\ing  been  necessarily  compared  with  the  series  of  Cap- 
tain CoEKE  on  board  the  ‘ Titania,’  and  that  vessel  lying  all  the  time  in  Santa  Cruz 
Roads,  at  the  eastern  end  of  Teneritfe  and  on  the  southern  coast,  while  the  Peak  is 
rather  towards  the  western  end  and  on  the  northern  coast ; — it  became  desirable  to  ascer- 
tain whether  any,  and  what  constant  differences  might  occur  between  that  station  of 
the  yacht,  30  miles  N.  60°  E.  of  the  Peak,  and  the  town  of  Orotava,  which  lies  only  at 
a distance  of  12  miles  and  in  the  direction  N.  30°  E. 
Facilities  for  this  purpose  were  afforded  by  Mr.  Feaxz  Keeitz,  a skilful  German 
watch-maker,  formerly  of  Hamburg,  who  zealously  undertook  to  observe  some  of  the 
instruments  kindly  lent  by  Admiral  Fitzeoy  on  the  part  of  the  Board  of  Trade. 
Having  established  these  instruments  under  good  circumstances  of  exposure  at 
M.  Keeitz’s,  on  August  29,  1 left  him  Avith  instructions  for  observing  them  simul- 
taneously to  the  ordinary  Yacht  times  of  observation ; and  on  September  24  he  furnished 
me  with  a series  of  readings  of  the  barometer  and  dry-  and  wet-bulb  thermometers, 
taken  three  times  a day,  or  oftener,  for  the  whole  of  the  intervening  period.  These 
observations  having  been  duly  corrected  for  index  errors,  and  reduced  in  a manner 
similar  to  the  Yacht  observations,  are  found,  on  the  mean  of  each  day,  to  give  the  follow- 
ing series  of  corrections  to  reduce  the  Orotava  series  to  the  Santa  Cruz : — 
Date. 
Barometer. 
Tempera- 
ture. 
Depression 
of 
dew-point. 
Date. 
Barometer. 
Tempera- 
ture. 
Depression 
of 
dew-point. 
1856. 
incites. 
1856. 
inches. 
August  30. 
+ "O-iS 
-6-1 
-6-7 
September  11. 
+ •063 
+ 0-1 
+ 2-9 
31. 
•134 
+ 0-6 
— 0-2 
12. 
•082 
— 0-8 
- 0-8 
September  1. 
•064 
— 2-4 
-0-4 
13. 
•107 
-3-0 
— 3-8 
2. 
•058 
-1-7 
+ 1-7 
15. 
•043 
+ 2-1 
+ 5-0 
3. 
•061 
-1-9 
+ 0-4 
16. 
•015 
+ 4-0 
+ 9-2 
4. 
•067 
-0-9 
+ 3-8 
17. 
•036 
+ 4-3 
+ 11-8 
5. 
•063 
— 0-4 
+ 3-3 
18. 
•062 
+ 2-0 
+ 7-3 
6. 
•047 
-1-6 
+ 1-2 
19. 
•074 
+ 1-2 
+ 2-9 
7- 
•078 
-1-7 
— 0-4 
20. 
•090 
+ 2-4 
+ 7-8 
8. 
•076 
— 2-0 
+ 0-4 
21. 
•063 
-0-9 
+ 1-6 
9. 
•051 
-1-6 
+ 1-9 
22. 
•083 
— 1-0 
+ 1-2 
10. 
+ •053 
— 0-8 
-O-l 
23. 
+ •099 
+ 1-0 
+ 1-8 
The  mean  barometrical  difference  appears  to  answer  very  closely  to  the  elevation  of 
M.  Keeitz’s  house  above  the  level  of  the  sea,  or  about  80  feet,  the  temperature  of  which 
3 z 2 
