4 TONGATABOO. 
I was desirous to pass over the positions of some of the doubtful 
shoals, and to verify the longitude assigned to Sunday Island, (the 
Raoul of D’Entrecasteaux.) Had this not been my design, I should 
have preferred pursuing a more eastern route than I did, which I am 
satisfied would have shortened our passage to Tongataboo. I do not 
conceive, however, that there is any difficulty in reaching that island, 
or any risk of falling to the leeward of it at this season of the year, for 
westerly winds prevail in its neighbourhood. We had a light wind 
from northeast to east-northeast. 
On the 11th April, we had reached latitude 29° S., longitude 178° 
W., and had on that day a most beautiful halo. It was formed at first 
of the segments of two great circles, the chords of which subtended an 
angle of 54°. These gradually united, and formed a circle around the 
sun, whose diameter measured 42°. Its appearances, at 2" 40™ and at 
3 p. M., are represented in the figure. 
The parhelia were very distinct, and had spurs on their outer sides ; 
two points in the vertical plane intersecting the sun, were very bright, 
but did not form parhelia; the sun’s altitude was 29° 20’: no decided 
clouds were to be seen, but the whole sky was hazy, and the wind 
fresh from the northeast. About two hours after this phenomenon, 
much lightning occurred, with torrents of rain, but no thunder, and 
this continued throughout the night. ‘The barometer stood at 29-99 in; 
DS! 
