® Yaanc Rropins om Howat, = 
‘SECOND SERIES. 
2 estates 
Without current, »  . itt Ah pha ba 
Current B, : i ‘ ’ ; 14:9 
Current A, . 4 ; @ ‘ ; 21:7 
* _ It is to be remarked, that here, if the principal sections of the 
made to act. 
Lastly, to obviate every objection, a third series of experiments 
was made by taking away the prism of flint-glass, and observing 
‘the deviations produced by the solar ray, when, as before, the 
electric current was made to in the wires of the electro-mag- 
net, now in one direction, now in another. 
Fs } Deviations. 
Current A... .16°5 As should be the case, the deviations are 
Current B. .. 16-8 ¢ equal, which proves that the electric cur- 
Current A... 16:8 ) rent and the magnet change the deviations 
in acting on the flint-glass and not in acting on the needle of the 
galvanometer. 
he above experiments establish, we believe, in an irrefragable 
manner, the rotation of the plane of polarization of heat under the 
It Influence of magnetism. 
= 
a3 
Arr. XX XV.—RHistorical account of the Eruptions on Hawaii ; 
ames D. Dana.* : 
be 
Tue island of Hawaii has a nearly triangular outline with the 
three sides fronting severally, west, southeast, and northeast. 
The western side is about 85 geographical miles in length, the 
southeast 65, and the northeast 75 miles. The whole surface 
pertains to the slopes of three lofty volcanic summits, Mount (or 
Mauna) Loat constituting its southern portion, 13,760 feet in 
height, Mount Kea, long extinct, covering the northern portion, 
13,950 feet in height, and Hualalai towards the western shores, 
estimated at 10,000. be ee 
Palins. er approaching Hawaii, while admiring the snblim- 
. ity of its swelling heights, is struck with the unbroken surface of 
the island. Lofty peaks and alternating valleys and ridges are 
SO geuerally characteristic of mountain scenery, that he views the 
even and gentle slope of the summits Loa and Kea with a degree 
* Extracted and condensed from the Author's Exp. Expd. Geological Report. 
+ This name is often written Roa. L and r are interchangeable letters in the 
Hawaiian alect. The | sound is most common, andds adopted in the written lan- 
‘Guage of the islands. 
