ì ä'/
I 1
530
d e d u c te d , from m y d e te rm in a tio n o f th e d ip , 12 ' fo r th e p ro b a b le
ch an g e b e tw e e n 1822 a n d 1826. A t Tene riffe th e d ip has b e en
fre q u e n tly o b s e rv e d ; b u t th e v a lu e s a ssig n ed b y different observers
v a ry so m u c h as to in d ic a te a m o re th a n u su a l fr e q u e n c y o f local
d is tu rb a n c e , w h ic h m ig h t also b e e x p e c te d from th e geological
c h a ra c te r o f th a t islan d . I t w o u ld b e u n safe th e re fo re to emp lo y
a n y d ip fo r th a t statio n b u t one w h ic h was c e rta in ly o b ta in ed a t
th e same sp o t a t w h ich th e h o riz o n ta l in te n s ity wa s observed.
T h e da te s o f th e observations a t th e se th r e e s tations fall b e tw e en
th e observ atio n s a t G re e nw ich in M a rch 1826, a n d th o se a t R io d e
J a n e iro in A u g u s t o f th e same y e a r. H a v in g th e in te n s ity a t
G re e nw ich = 1,372 a n d a t R io = 0 ,884, a n d th e d ip a t G re e nw ich
69° 5 2 ', a n d a t R io 1 4 ) 0 0 , w e h av e th e tim e o f v ib ra tio n o f C ap ta
in K in g ’s c y lin d e r as a d ip p in g n e ed le a t R io a t th e re sp ec tiv e
d a te s as follows, n am e ly ,
M a rc h 1 8 2 6 .............................................. 536,2.
A u g u s t 1 8 2 6 .............................................. 537,0.
I t a p p e a rs th e re fo re th a t b u t a v e ry s lig h t c h an g e to o k p la c e in
th e m a g n e tism o f th e c y lin d e r d u r in g th e o u tw a rd voyage, a n d we
m a y ta k e 5 3 6 ,6 as th e tim e o f v ib ra tio n a t R io , c o rre sp o n d in g to
th e da te s o f th e in te rm e d ia te o b serv atio n s; a n d th is is d one in th e
ta b le fo r M ad e ira a n d P o r t P ra y a .
T a b l e I .
Rio de Janeiro.
Time o f Vibration.
Interval. Loss. Per Diem.
Horizontal. As a Di|)ping
S. S. D a y s . S.
A u g u s t 2 9 , 1 8 2 6 . , . 545,2 537,0
S e p t e m b e r 1 5 , 1 8 2 7 5 5 1 , 7 543,5 / 3 8 2 6,5 •0 1 7
D e c e m b e r 2 1 , 1 8 2 8 5Ö 1 ,» 5 5 2 , 7 4 6 2 9, a ‘0 2 0
J u n e i j 1 8 3 0 . . . . 5 6 3 , 8 555,4 5 2 7 2,7 • 0 0 5
T a b l e H .
Time o f Vibration. Intensity.
At the Station. At Rio.
Station. Date.
Horizon.
As a
Dipping
As a
Dipping
Rioi=l,000.
Needle. Needle. 2
S. S. S .
ItTnilpiTa. . . . . . . . . 18 2 6 M a y 31 6 2 7 ,7 9 AIO 1 1 «;<;6 1* ,10*/7 7/
P o r t P r a y a . . . 1 1 8 2 6 J u n e 2 2 )
an d 2 4 / 5 5 7 ,0 8 4 6 5 ,4 5 3 6 ,6 1 ,3 3 0 1 ,1 7 7
St® C a t h a r i n a 1 8 2 7 N o v . 3 5 5 3 .5 8 5 3 2 ,7 5 4 4 ,5 1 ,0 4 5 0 ,9 2 0
G o r r i t i ...........^
1 8 2 6 O c t . 2 9 /
a n d N o v . 6 / 549,44 497,0 5 3 8 ,1 1 ,1 7 2 -t
1 ,0 4 1 — ....... 1829 J a n , 10 5 6 2 ,7 8 6 0 9 ,0 5 5 2 .8 1 , 1 7 9 /
M o n t e V i d e o 1827 D e c . 18 5 5 3 ,8 7 4 9 6 ,7 5 4 5 ,4 1 ,2 0 6 1 .. ................... 182 8 O c t , 8 5 6 0 ,9 5 5 0 3 ,0
5 0 6 ,6
5 5 1 ,3 1,2 0 1 > 1 ,2 0 3 1 ,0 6 5
— ............. 1 8 3 0 J u n e 1 5 6 4 ,8 9 5 5 5 ,4 1 ,2 0 2 J
S e a B e a r B a y 1 8 2 9 M a r . 20 5 7 6 ,3 7 4 4 6 ,0 5 5 3 ,1 1 ,5 3 8 1,361
S t . M a r t i n /
C o v e ...........(
182 7 J a n . 15 i
a nd 2 2 J 5 8 4 ,2 9 4 1 4 ,9 5 3 9 ,4 1 ,6 9 1 -,
— M a r . 2 7 5 8 5 ,0 8 1 ,4 9 8 4 1 5 ,4 5 4 0 ,6 1 , 6 9 4 /
P o r t F a m i n e 182 8 J a n . 28 5 8 9 ,3 6
5 9 6 ,5 4
4 1 7 ,5 5 4 6 ,2 1 ,7 1 2
— ................. — M a y 8 4 2 2 ,6 5 4 8 ,2 1,683- i
- ........{
— J u n e 1 8 /
a n d J u l y 3 0 / 5 9 5 ,8 1 4 2 2 ,1 5 4 9 ,3 1 ,6 9 4 > 1 ,7 0 0 1 ,5 0 5
1 8 3 0 A p r i l 26 5 9 8 ,9 7 4 2 4 ,3 5 5 5 ,1 l , 7 1 2 j
C h i l ó e ...........
1 8 2 9 S e p t . l ì
a n d D e c . 1 5 / 5 6 5 ,2 3 453,7 5 5 4 ,2 1 ,4 0 2 1,321
J u a n F e r n a n d e z 1 8 3 0 F e b . 19 5 5 1 ,8 3 4 6 4 ,7 5 5 4 ,8 1 ,4 2 5 1 ,2 6 2
T a l e a h u a n o 1 8 2 9 D e c . 18 555,59 4 6 6 ,5 5 5 4 ,6
— .................. 1 8 3 0 M a y 12 5 5 7 ,1 8 4 6 7 ,4 5 5 5 ,3 1 , 4 1 2 /
1 , 2 5 0
V a l p a r a i s o . . . 1 8 2 9 A u g . 4
1 8 3 0 J a n . I l l
an d F eb . 1 J
5 4 8 .5 9
5 5 1 .6 0
479,5
4 8 2 ,1
5 5 3 ,9
5 5 4 ,6
1, 3 3 4 1
1 , 3 2 4 /
1 ,1 7 6
'I
to ;,,
. r. r
■,h :