Antarctic Expedition. 
231 
Observe indications of extinct, and of quiescent volcanoes. 
If vapours issue from the earth, observe their effects on the 
adjacent rocks, and procure specimens of the altered and un¬ 
altered stone; note the distance to which the change extends. 
Where volcanoes are actually in eruption, record accurately 
the date and duration of their paroxysms; and, when the in¬ 
tensity varies, note the time of the greatest violence, and 
contrA . 
Ascertain whether Neptunian substances are to be met with 
amid the detritus of volcanic islands; or volcanic substances 
amid the detritus of coral islands, &c. 
Among the ejected masses, both of active and extinct vol¬ 
canoes, many crystalline minerals may be expected. The 
masses should be broken, and closely examined with a view to 
their discovery. 
All the lavas of existing currents—volcanic glass, obsidian, 
pumice, &c.—should be carefully observed, collected, and 
examined for crystals. 
Phenomena indicating former earthquakes should be care¬ 
fully inquired after, and noted; and, in inhabited countries, an 
attempt should be made to ascertain the traditions on this point. 
If dykes of lava, or of trap, traverse other rocks, ascertain 
whether any changes have been produced in the latter. Ob¬ 
tain specimens of the dykes, and of the altered and unaltered 
rocks. 
Mineral springs, hot springs. —Note their occurrence, the 
rocks from which they issue, and obtain a large bottle of the 
water; also specimens of the sediment deposited by them. 
Record their temperature; the volume of water thrown out; 
whether they are uniform, or intermittent; whether gas be 
disengaged £rora them. 
4. Heads of Inquiry at Specific Places. 
Van Diemen 7 s Land .—The prevailing strata near Hobart 
Town contain shells resembling those of our carboniferous 
series; a full collection of these, especially from some distant 
part of the island (as the formation extends to the northern 
shores), would be very interesting. About a mile north of 
Hobart Town there is one small quarry of travertine limestone 
(burnt for lime), which contains the leaves of plants not now 
found in that country ; it is said that shells (and bones.) have, 
though rarely, been found in it: these, especially any bones, 
and the leaves, are deserving ot careful collection. On the 
shores of Storm Bay there are obscure appearances of a raised 
beach. Some miles east of Ilobart Town there is said to be a 
great accumulation of oyster shells, which have been quarried 
for lime. Ascertain if all these shells are of recent species. 
In the northern parts of the island large caverns are said to 
exist in the limestone formation : the great probability of their 
