496 
DRS. T. ANDERSON AND J. S. FLETT ON THE ERUPTIONS OF THE 
gentle, but enough to ripple the water and fill the sails. We had drifted out from 
the shore, so we gave our boatmen instructions to keep the boat close-hauled, and 
draw in to the land, as the cloud was passing more to the westward. Then, when we 
looked at the cloud again; it was changed, it showed no more the boiling, spouting, 
furious vigour, but the various rounded lobes in its point swelled slowly and to 
greater size, while fresh ones did not shoot forward, and the mass had a more 
reposeful and less violent appearance. In the moonlight it was difficult to say how 
far away it was, but judging by our distance from the shore, we thought it was a 
mile oft', or rather more. 
It now lay Ijefore us nearly immohile, a gigantic wall, curiously reflecting the 
moonlight like a pall of black velvet. Its surface was strangely still after the turmoil 
it had exhibited before, and great black rounded folds hung vertically like those of 
an enormous curtain. This lasted a few minutes, aiid the folds became flatter and 
less convex, and a strange shimmering and change of colour began to steal through 
the great murky wall, like a transformation scene. It became brownish in places, and 
in others grey, or even white on the edges of the folds, and through the whole vast 
face of the cloud these changes gradually spread. Soon it was evident that the base 
was darkei', and the paler summit was rising in the air and soaring obliquely upwards 
aiid forwards. The dust wms sinking, and the pale steam set free from entanglement 
with the heavier solid particles, was followdng its owui natural tendency to ascend, 
wdiile still impelled forwards by the great onward impetus it had received. 
The steam cloud crept southward, and wars soon directly over our mast-head, 
travelling with a velocity of perhaps 20 miles an hour. It was grey and tongue- 
shaped, with a Idimt, rounded apex, and at its sides and beneath it there were bars of 
fleecy white where the moonlight fell upon its thin edges and the lohes which hung 
beneath it. The mass of the cloud was slaty-grey, and as we looked up at its slightly 
I'ounded under surface we coidd see that still through it the expansive energy of the 
vapours was working everywhere, and many rounded convolutions were forming 
especially on its front, though no longer with the rapidity that they had formerly 
exhibited. 
The lightnings were now reduced in number and frequency, but still, in branching 
tortuous lines, threaded the dark mass in every direction. A low rumbling noise was 
given out as the cloud worked its way across the clear, starry sky. In a little while 
it ol)scured the moon, and the niglit became very dark. It spi'ead and spread, 
la‘oadening and elongating till in a great, flattened, rounded mass it covei-ed the whole 
sky, and in an hour or two only a narrow crescentic belt of stars could be seen au'ay 
down on the southern horizon. The low rumbling noise continued, and the lightnings, 
though less numerous, were visible for a long time almost continuously flashing. 
As the cloud reached the zenith a hail of pebbles fell in the sea and on our decks. 
We picked up the first that fell. It was about the size of a chestnut, and was cold to 
the touch, so we knew that we were safe. Then smaller pellets rattled on our decks. 
