464 MAJOR H. DE HAGA HAIG ON THE [Aug. 1 895, 



because their flora and fauna have so much in common and distinct 

 from what is found elsewhere, but the results of these soundings 

 -do not lend any support to the theory. 



The mountains of Mauritius consist of superimposed lava-flows, 

 generally with burnt volcanic ash between the layers. They 

 are very precipitous, especially on the seaward side, though they 

 nowhere reach the coast. The most peculiar of them is the 

 well-known ' Pieter Both ; ' this is a wall-like mass, culminating 

 in a triangular pyramid, surmounted by a huge block of lava which 

 has the shape of a pegtop standing on its point. From every point 

 of view this curious mountain resembles something different : now 

 it is an old woman wrapped in a shawl, then a most striking stand- 

 ing statue of the Queen with long train and a regal air. From 

 another spot it is an immense, meagre, sitting figure, resting its 

 feet on a footstool. Another strange rocky mountain is the ' Corps 

 de Garde,' so called from its extraordinarily exact profile in high 

 relief of a recumbent figure of a man in the uniform of the old 

 French Guard, with high boots, three-cornered hat, and arms folded. 

 The figure from another point of view resembles a bust of King 

 Louis Philippe, with an immense shirt-ruffle and a wig. 



Isolated hills ending in a conical shaft of rock occur in many 

 parts of the island, and are no doubt the remains of the central 

 cores of ancient volcanos. There are a number of very perfect 

 craters, most of which are still clothed with dense forest, and 

 some few enclosed lakes, the best known of which are the ' Grand 

 Bassin,' the ' Bassin Blanc,' and the ' Trou aux Cerfs.' 



The neighbouring island of Bourbon still contains an active 

 volcano, whose eruptions are of frequent occurrence, and it seems 

 probable that both islands are on the same line of action of the 

 subterranean force which has thrown them up. So we may regard 

 this active crater as the safety-valve which prevents the doubtless 

 diminished subterranean heat from venting itself on Mauritius. 

 Were the Bourbon volcano to become choked from any cause, there 

 might be danger to the sister isle. It is evident that the volcanic 

 fires beneath Mauritius are merely dormant, not extinct, for they 

 have several times manifested themselves by earthquakes, for 

 example on May 15th, 1854, August 24th, 1860, and January 6th, 

 1863. These shocks, however, were very slight, else they would 

 have shaken off the Pieter Both's balanced knob. 



The elevation of the central ridge of Mauritius causes the 

 moisture-laden south-easterly trade winds, which blow over it during 

 nine months of the year, to rise ; consequently their tempera- 

 ture is reduced, their moisture is precipitated, clouds are thus 

 formed, and a very heavy rainfall ensues. This, combined with 

 the steepness of the river-beds, sometimes so great as 1 in 15, 

 causes the cutting force of the streams to be very powerful. They 

 have dug out for themselves immense ravines : that through which 

 the Tamarin river runs is 1160 feet in depth, while the Black 

 Pbiver gorges are upwards of 2000 feet deep, and there are few 



