74 Proceedings of the Eoyal Society 
mud, and blue mud of considerable consistence, in the form of boul- 
ders, with fresh water, debris of vegetable matter, decayed, and in 
some instances green and fresh. These bubbles are not confined 
to the seaboard, but are, I am inclined to think, both more active 
and numerous in the bed of the roads with the flagstaff bearing from 
E.N.E. to the south, until it bears N.E. by N., or even south of 
that. About five years ago, for about four miles down the coast, 
and from the beach out to sea for a mile and a half, the sea was no- 
thing but liquid mud, the fish died, and as these cones reared their 
heads above the surrounding mud, they would occasionally turn 
over a dead porpoise and numerous fish ; the boatmen had consider- 
able difficulty in urging their canoes through this to get outside of 
it ; the beach and roads presented then a singular appearance ; no- 
thing to be seen but those miniature volcanoes, some silent, others 
active ; perfect stillness of all around the ships in the roads, as if 
in some dock, with a heavy sea breaking in seven fathoms outside. 
“ There are numerous deep holes, some of them I measured in 
1852 ; one in particular, just at the end of this canal, had as much 
as 60 feet in depth ; these holes may, or may not, communicate 
directly with the roads, but X think it will be found that the prin- 
cipal source of active communication is more inland, and the back- 
water perhaps only an auxiliary. About three miles above Ohen- 
ganoor, in the river of that name, there are one or two deep “ Linns” 
which I only had an opportunity of visiting twice ; the first time 
I had not the means of ascertaining the depth, the next I lost both 
lead and line. 
“ The depth of this passage is not so great as you approach the 
beach, as noticed above; for, while extending the canal from the 
Timber Depot in March last, about 200 yards from the beach, at 12 
feet we suddenly and unexpectedly broke through the substratum, 
when a column, fresh water, mud, and vegetable debris, and about 
nine inches in diameter, spouted up, which, when left alone, gra- 
dually subsided as the upper stratum of sand filled in round the 
column of the spring. 
“ I submit the above information, as I feel that it will be inte- 
resting, both to yourself and Government, to pursue the investiga- 
tion of this subject more efficiently. I have omitted to state one 
important particular, — that is, should no rain fall, as has been the 
