Boating on a Boiling Lake.

Roto-mahana, the “Warm Lake” of the Maoris, is the most singular example of a volcanic lake in the islands, for it has been subject to extraordinary changes during a marvellously brief period. Before the Tarawera eruption in 1886, Roto-mahana was but a small, shallow, reedy lagoon of about a mile in length. When Tarawera burst out a huge rift split the mountain from end to end and extended down into the lake at its foot. The waters of the lake, so suddenly gaining access to the hidden fires below, were converted into steam, and then up went the lake bottom and the islands and the terraces on its margin, hurled into the air to deluge the land for many scores of miles. The new Roto-mahana is six miles long, and several hundreds of feet deep. Along the northern and western shore line there is a zone of tremendous hydro-thermal activity. Here one may boat for two miles along geyser-pitted cliffs, strangely painted by chemical action. The cliffs are steaming from lakeside to skyline, and thousands of warm vapour-wreaths curl like white smoke into the upper air. Nor is the heat confined to the cliffs. The water on which you are floating is boiling in many places, and here and there you feel below your boat the thump of water-hidden geysers.