of them are small and local, but others are far more violent than earthquakes due to explosions of steam, and, as the centrum is often deeply seated, they are often felt over a very wide area.

The earthquake of Wellington in 1855 was one of this kind, as also are, no doubt, most or all of those in the South Island. The Wellington earthquake, however, belongs to a very rare class, in which the centrum extends to the surface, and surface-rocks are moved. In a large majority of cases no movement takes place in the surface-rocks^* except that due to the earth-wave generated below by the fractures.

Small earthquakes may not be accompanied by actual fracture of rocks; and when there is no fracture no noise will be heard, although the shock may be felt for a considerable distance: for the waves of sound in the earth are produced by the fractures.

In the earthquake we are now considering the shake was of an unusual character, inasmuch as it was long and even, without any violent jerks; but, as it was accompanied by a sound-wave, fractures of some kind must have taken place. These fractures could not have been due to an explosion or to a very sudden break or split: they appear to me to have been due to a slow splitting or crushing of rocks.

At first sight the evidence seems to favour the idea of a slow splitting having taken place along an east-and-west line in the valleys of the Waiau-ua and Hanmer, for it was in this direction that most of the damage was done. But this idea is much weakened when we remember that this is the only line which is even fairly well inhabited, and is the only line along which an alluvial valley approaches the epicentrum; and when we examine the evidence attentively I think we must give up the idea altogether. It is certainly in favour of it that a better explanation could then be given of the destruction caused at Woodbank; but this is the only favourable fact that I can find, for no fault or fissure has been proved from other evidence to exist in the valleys of the Waiau-ua and Hanmer, and no fracture or movement of solid rock has been found anywhere in the neighbourhood. On the other hand this line has a distinct meizoseimal band, and if it were a line of fissure reaching to the surface the shock would have commenced at this band and gone both ways, which is distinctly contradicted by both an eye-witness and by time-observations. Again, the Ferry Hotel stands on the very edge of this supposed fissure, and ought to have suffered more than Leslie Hills or Highfield. And, again, no explanation is in this way given of the strength of the shock at Tekoa and in the Otira,