March i, 1888.] THE TROPICAL 
SPONGES AND SPONGE DIVERS: 
THE DEPTH WHICH DIVERS CAN 
SAFELY ACCOMPLISH. 
A correspondent, in sending u ; a portion of the 
Daily telegraph of December 23rd, with the 
interesting article (quoted below) on sponge 
fishing and the nature of the very low marine animal 
organism callod sponges, — some of which are vory 
beautiful, but useless, and others not handsome, butex- 
ceedingly valuable for domestic and surgical purposes, 
—asks, with reference to the alleged depth of 175 feet 
to which sponge divers in the Levant are said to 
descend: "How dues this compare with Ceylon 
pearl divors?" Wo can reply at once that it is 
not a matter of comparison but of violent con- 
trast. The average depth of water over the banks 
on which diving for pearl shells is conducted in 
India and Ceylon is 42 feet, the oysters being 
found at from 0 to 10 fathoms, that is from 30 
to 00 feet ; and we have never heard of divers 
(without artificial appliances) going deeper than 
If) fathoms or 1)0 feet. If, as is stated, the divers 
in the Levant descend to a depth of 17", feet, 
that is '2'.) fathoms, or very nearly twice the maxi- 
mum depth we have mentioned, we can imagine 
a rapid enough descent to that depth by aid of 
a stone, but can equally realize a pressure at 
such a depth which would render the subsequent 
ascent very difficult. The average time taken in 
the Levant for an ordinary dive agrees almost exactly 
with that occupied by the pearl divers of the Indian 
seas, so that we take it for granted that 
dives to 175 feet, the depth where abundaut sponge- 
growth ceases, must bo exceptional and rare. 
Sponges are, equally with corals, sea anemones 
and shells, amongst the submarine growths in Ceylon, 
and some of the chank shells taken up during the 
ls*7 lishery had sponges attached to them, curious 
as natural objects, but not valuable for domestic 
purposes. Wo remember, however, a few years ago 
seeing offered for sale a collection of sponges, small 
in size, but of very fair quality (soft and com- 
pressible), which had been collected on the reefs 
between Irincomalee and Mullaittivu, where sponge 
gathering was and perhaps still is (?) subsidiary to 
shell collecting. The family of sponges are deemed 
lower in tho scale of animal life even than the 
zoophytes, propagation taking place by gemmules 
as well aB by true ova, so that we suppose the sponge 
constitutes one of the nearest links between vegetable 
and animal life. As a general rule corals, sponges and 
shells do not seem to flourish at a depth much 
beyond the influence of full light, so that collectors 
have seldom to dive farther down than ten fathoms. 
Now that tho question has been raised, can any 
scicntilic friend tell us tho depth which can be 
reached in sea water, so as to avoid the limit (which 
wc snpposo must exist?) where mere superin- 
cumbent pressure would prevent re-ascension, even 
if death did not result from asphyxia? Wc know 
that at tho latest Ceylon pearl lishery a diver 
(ar exceeded tho local record by remaining under 
wuii'i- for lO'.l seconds, and wo suspect tales of 
ability to live without breathing for twico or thrice 
this period must be apocryphal. Let us suppose 
a limit of two minutes, or 120 seconds. In view 
of 109 seconds actually accomplished, 11 more 
seconds might possibly bo endured. Hut to what 
./ ftfi can an unprotected human being descend 
in the sea, with tho certainty of natural buoyancy 
sufficing to carry the body again to the surface, 
in resistance of the superincumbent weight ? There 
BUMt bo some record of experience or some for- 
mula by which the question can bo answered? 
In the article "Sponge" in Chambers'.; Encyclopedia 
(whore, by the way, iho illu.ualiou of living sponges 
77 
AGRICULTURIST. 609 
closely resembles a representation of miniature 
volcanic craters ejecting showers of stones) we see 
it stated that a sponge was brought up from a 
depth of 185 feet in the Gulf of Macri, This 
refers, apparently, to ordinary diving. A man can, 
therefore, descend 185 feet, secure an object and 
come to the surface again. Could he go safely 
beyond 200 feet, and at what limit would pressure 
from above keep him below, and how far would 
he sink before pressure from below would arrest 
tho sinking process? Can these questions be 
answerod ? Of course we speak of an average 
human being with normal organs, but trained to 
diving. 
THE SPONGE FISHERY. 
Some interesting particulars relating to the Levant 
sponge fisheries have been recently given by the United 
States Consul at Reyrout. It will be remembered that 
at the Fisheries Exhibition one of the most notable 
items of that varied show was a large model, very 
perfect to the minutest detail, demonstrating by what 
methods that strange, porous, cataractal living thing 
called the sponge is angled for and taken. Unfortu- 
nately, however, there was nothing in the model itself 
to let the spectator know how marvellous a piece of 
organisation the sponge is, though some idea could be 
formed of the picturesqueuess of tho art of fishing for 
it. Familiarity neutralises the appreciation of much 
that is wonderful. The sponge to most people is merely 
a useful and pleasant article of the toilet. Imagination 
will not carry them beyond that. Whence the soft 
mass they squeeze came, whether it be a fish or a 
vegetable, where it is to be met with, what aspect it 
presents whilst under water, naturally concern many 
as little as the manufacture of the tooth brush or the 
method by which combs are made. Yet the spongn 
is quite worth knowing something about. The fishery 
according to the United States Consul at Beyrout, 
extends along the coast of Baytroon, Tripoli, Latakia, 
and the Island of Iluad north of Tripoli. Most of 
the trade is carried on by the Syrians, but many 
Greeks from Rhodes, Samos, and other places adjac- 
ent share in the toil. The boats used by the men 
are from eighteen to twenty feet long with four or 
five of a crew to each little craft. The season starts 
in June, and the catch continues to the end of Octo- 
ber, uot because the sponge like the herring or 
the mackerel is only to be taken at certain periods, 
but because the weather between those months 
is usually tine and the water smooth enough to suffer 
tho fishermen to ply their trade without dinger. 
Early in the morning, at the first peep of dawn, the 
boats start away for the grounds, and they continue 
to fish until suudowu. As the work is carried on by 
diving, the labour, as may he supposed, taxe9 the 
strength so seriously that this kind of fishing is only 
practicable by young and middle-aged men of great 
physical robustness and strength. The period during 
which the diver remains under water averages from 
sixty to eighty seconds. His sole equipment consists 
of an open net, adjusted round the body so as to form 
a pouch, aud tho men are said to uso no instrument 
of any kind in collecting the spougeo. The depth to 
which they descend varies from twenty-five to a 
hundred and seventy-live feet, below which there 
aro no sponges worth taking to be found. Three 
kinds are known in lleyrout, of which the 
red sponge taken near Baytroon is tho most 
esteemed. The average auoual catch is estim- 
ated at about thirty thousand pouuds in value, but 
perilous as tho pursuit is, the poor fellows who follow 
it are mulcted In a fu of ton per cent, upon the gross 
Value Ol the catches by the local authorities. 
It was formerly supposed that the l'orifera or sponges 
belonged to the vegetable kingdom, but their animal 
nature h is Imig been established. Thoy are gelatinous 
in their inception, and, from the sticky mucous mutter 
which forms their primitive organism, the Solid parts 
are deposited, whence proceeds the whole grow lb o! 
tho mass. Microscopic inspection of the spouRO dis- 
covers a wonderful composition of fibres of varying 
