THE COMMERCIAL SPONGES AND THE SPONGE FISHERIES. 489 
tiveness, the charge being made, apparently with justice, that it tears loose or 
crushes all sponges in its path, both large and small, and that not only is a con- 
siderable portion of the catch inferior on account of the small size, but that many 
sponges are torn loose and not brought up at all, being left to die on the bottom 
or to become rollers. In some localities the gangava is prohibited in depths less 
than a prescribed minimum. In Egypt the limit is fixed at 80 meters (262 feet), 
and in Cyprus the instrument is entirely prohibited. It is used principally on - 
the African coast and on the banks of Lampedusa. 
There are probably between 400 and 500 dredges or gangavas employed in 
the sponge fisheries of the Mediterranean, of which the great majority come from 
the Sporades and Cyclades. 
Machine diving.—This method of diving and the apparatus employed is 
sufficiently described in that part of this paper treating of the Florida fisheries. 
The scaphander was introduced into the Ajgean and the Levant about 1866, 
and at once came into such general use among the Greeks that ten years later 
about 110 machines were in active service. In 1907 it was reported that there 
were from 100 to 120 diving machines for sponge fishing owned in Greece alone. 
In 1903 there were 158 diving outfits employed in sponging under the Greek 
flag, the reduction in 1907 being probably due, at least in part, to the export of 
apparatus to the United States for use in Florida. 
From the time of its introduction the diving dress has met with active and 
sometimes violent opposition from the spongers using the older methods, who 
charged it with being destructive to the sponge beds. Recently it has been 
opposed on hygienic grounds, and, mainly through the efforts of Mr. Charles Flegel, 
since 1892 its use has been prohibited in Austria-Hungary, Egypt, Crete, and 
Samos. ‘Turkey also passed prohibitive laws, but they were not enforced and 
have been repealed, and the interdiction formerly existing in Cyprus has been 
removed. Italy and Greece have placed restrictions on the depth to which the 
divers may go, and both have vessels to enforce the law, which, however, is 
more or less generally ignored. The Greek regulations prohibit all diving at 
greater depths than 127 feet, and at least until recently regulated the period for 
which the diver could remain submerged at various depths. During the 
sponging season the Greek Government maintains a hospital and hospital ship 
on the African coast to provide medical attention and succor to the divers. 
Some divers are injured or killed by accidents to the diving dress or hose, 
but the chief danger to which they are exposed is caisson disease, which is a 
frequent consequence of working in depths of over 60 feet. This malady is 
caused by the absorption of gases from the compressed air and their release as 
bubbles in the blood vessels and tissues upon decompression, especially if the 
latter be rapid, asin the quick ascent of a diver from the bottom. In caisson 
