COMMERCIAL SPONGES 749 



A new type of mechanical diving aid, known as the Fernez apparatus, has 

 come into use in the Mediterranean since about 1912. The diver is naked, except 

 for a rubber mask fitted with goggles, air valves, tubes, etc., and the air is car- 

 ried from a small pump on the boat, through a hose, to a small reservoir attached 

 to the back by a belt, and thence to the mask and its respiratory appliances. It 

 compares favorably with the diving suit at equal depths, usually from 65 to 130 feet. 



Dredging or Trawling. This method of sponging is confined to the Mediter- 

 ranean, where it is practiced principally by Greeks and Sicilians. The dredge, 

 gangava of the Greeks, or gagova or cava of the Italians, is a special type which 

 has been developed for this fishery. The frame consists of a heavy round steel 

 bar about 35 feet long and 2/2 inches in diameter, bent at right angles about 12 

 or 15 inches from each end. These turned-up ends are formed into sockets, into 

 each of which a stout wooden stake is driven and secured by metal pins or bolts. 

 The bar and stakes form the lower side and ends of the frame, the upper part of 

 which is a wooden beam about 6 inches in diameter, with rabbets near the ends 

 to receive the tongues or flattened ends of the lateral stakes. There are several 

 transverse steel struts connecting the steel and wooden bars, the whole forming 

 an open rectangle about 32 feet long and 20 inches wide. To this frame is attached 

 a quadrangular net of rope, with a mesh of from 2/2 to 3/2 inches bar. A bridle is 

 formed by a rope running from the middle of the wooden beam and 3 or 4 chains 

 attached to the steel bar near the ends and at 1 or 2 intermediate points, all united 

 in an eye or ring to which the towing warp is attached. 



This apparatus is towed at a speed of about 1 to 1/2 knots per hour by saihng 

 vessels of about 20 to 40 tons burden, fitted with 3 winches and the necessary 

 davits and towing bitts, which cannot be described in detail within the limits of 

 this chapter. When in use the relative lengths of the several members of the bridle, 

 the buoyancy of the wooden beam, and the weight of the steel bar, keep the frame 

 erect with the bar scraping the bottom and tearing loose the sponges and other 

 organisms on the bottom, which are retained in the bag. From time to time the 

 gangava is hauled aboard and the contents of the bag discharged on deck and 

 sorted, the sponges being retained and the considerable quantity of debris dumped 

 overboard. The crews consist of about 6 men each. 



Preparation of Sponges for Market 



The preparation of sponges for market is a comparatively simple process. When 

 taken, the living sponge is covered with a "skin" or membrane, and a large part 

 of the interior is filled with a soft, pulpy, fleshy substance. Both of these must be 

 removed, leaving the skeleton clean. The sponge is first killed and then macerated 

 to liquefy the putrescible matter which is then washed and squeezed out. 



The hookers in Florida formerly killed their sponges by prolonged exposure to 

 the air, "roots" down, on the decks of their boats, after which they placed them 

 in "crawls" about 10 feet square, made by driving mangrove stakes close together 

 in shoal water. After an interval of about a week they were removed, beaten with 

 a short heavy stick and squeezed repeatedly under water. When properly done this 

 removed the fleshy matter thoroughly; but the sponges often accumulated much 

 sand from rolling on the sandy bottom of the crawls. 



When diving became common on the Florida coast, the Greeks introduced the 

 methods used in the Mediterranean: The sponges are placed on deck and killed 



