18 The Australasian Scientific Magazine. [August i, 1885. 
should be carefully noted, as well as the depth of the water lound them ; 
their harbours and facilities for landing ; what supply of water can be had , 
whether near the shore or not, or whether convenient for watering ships, 
etc.- what rivers or streams (if any) are met with, as well as their natural 
productions. Reefs and rocks, whether visible, or sunken, and constantly 
below the surface of the water, as well as shoals, should be examined and 
described, and the depth of water over them carefully ascertained. 
In concluding with this subject, I would also mention a few points 
connected with the physical features of the country, which, being of an acci- 
dental rather than a normal character, did not easily find a place in the more 
obvious subdivisions of the subject. I he traveller should pay particular 
attention to these phenomena in the physical structure of the country, which 
are called, by some persons, natural curiosities. Amongst the principal of 
these are grottoes, caves, and caverns ; some of them are not only stnkingly 
beautiful, but of great scientific interest. They are more usually met 
with in limestone districts than in any other ; it is interesting to ascertain 
their size and extent, and the distance to which they have been tiaced. 
Are they traversed by subterraneous streams, and if so, do those streams 
enter or escape by known channels or mouths, as is frequently the case in 
the west of Ireland ? Natural bridges present another instance of this kind 
of phenomena. How have they been formed, and what is the nature of the 
rock of which they consist ? Are they stalactitic, or of a more compact 
nature ? Mines are also to be noticed, although they come more directly 
under the head of geological observation ? All volcanic phenomena and 
earthquakes are also deserving of notice. Springs of fresh water rising up 
in the sea are not of unusual occurrence ; and any information respecting 
them is always desirable, such as the depth of water, and the effect of fiesh 
water on the surrounding ocean. In short, it may be safely asserted that 
there is no single fact connected with the physical structure of the earth, 
falling under the notice of an intelligent observer, which may not be of 
value or importance either to himself or others, if he will only give himself 
the trouble of carefully noting it down on the spot, with as much accuracy 
and detail as circumstances will permit. <c Trust nothing to the memory ; 
for the memory becomes a fickle guardian when one interesting object is 
succeeded by another still more interesting.” 
