I've seen, at other volcanoes, pieces of pumice blown up so high that they've been caught by the upper currents of the atmosphere and carried away in an opposite direction to the wind that was blowing below at the time.

Ay, I believe that dust is sometimes blown _miles_ up into the air." As Captain Roy thought that the merchant was drawing the long bow he made no reply, but changed the subject by asking what was the height of Perboewatan.
"Three hundred feet or thereabouts," replied his friend.
"I hope my son will have the sense to clear out of the island if things look like gittin' worse," muttered the captain, as an unusually violent explosion shook the whole side of the cone.
"No fear of him," returned the merchant.

"If he is visiting the hermit of Rakata, as you tell me, he'll be safe enough.

Although something of a dare-devil, the hermit knows how to take care of himself.

I'm afraid, however, that you'll not find it so easy to 'look up' your son as you seem to think.