73 
of Edinburgh, Session 1872 - 73 . 
In Lieutenant Taylor’s chart of 1859, the bank is shown off the 
town of Allippey in lat. 9 o, 30. But, since then, it has moved four 
miles to the south, where it was when I examined the place, along 
with Mr Crawford, in March 1871. A letter from that gentleman 
in 1860 to the resident at Travancore gives the following account 
of this bank, with some of the theories which have been started 
in connection with its properties : — 
“ Lieutenant Taylor attributes the smoothness of the water to 
the soft mud at the bottom, by which, when i stirred up by a heavy 
swell from seaward, the activity of the waves is so deadened as to 
render the shore-line free from surf.’ I regret never having met 
Lieutenant Taylor. 
“ A number of years ago I brought to the notice of G-eneral 
Cullen, that the perfect smoothness of the water in the roads, and 
at the beach at Allippey, was attributable, not to the softness of the 
mud at the bottom so much as to the fact of the existence of a sub- 
terranean passage or stream, or a succession of them, which, com- 
municating with some of the rivers inland and with the backwater, 
become more active after heavy rains, particularly at the com- 
mencement of the monsoon, than in the dry season, in carrying off 
the accumulating water, and with it vast quantities of soft mud. 
General Cullen, the resident, sent a quantity of piping and boring 
apparatus in order to test the existence, or otherwise, of what I had 
urged. Accordingly, I sunk pipes about 700 yards east from the 
beach, and at between 50 and 60 feet depth ; and, after going 
through a crust of chocolate-coloured sandstone, or a conglomerate 
mixture of that and lignite, the shafting ran suddenly down to 80 
feet ; fortunately, it had been attached to a piece of chain, or it 
would have been lost altogether. Several buckets from this depth 
were brought up, which correspond in every respect with that thrown 
up by the bubbles as they burst at the beach, which I shall here 
attempt to describe as accurately as I can. Due west of the flag- 
staff, and for several miles south, but not north of that, the beach 
will, after or during these rains, suddenly subside, leaving a long 
tract of fissure, varying from 40 to 100 or 120 yards in length ; the 
subsidence is not so quick at first ; but, when the cone of mud once 
gets above the water, the fall is as much as 5 feet in some instances, 
when the cone bursts, throwing up immense quantities of soft soapy 
