196 BULLETIN OF THE BUREAU OF FISHERIES 



is seen from the fact that none has persisted, for we find that during the eighteenth 

 century the sheathing generally in use "was a doubling of the skin of a ship with 

 wood, which was kept constantly payed with tar and grease, or mixtures of such 

 compounds." 



The prevention of fouling, then, has been a problem persisting through the 

 centuries, which has taxed the sldll of ingenious sea captains for hundreds of years; 

 and the fact that it still occurs indicates the extremely difficult nature of its solution. 

 In earlier times it was the general practice for vessels to be cleaned by the scouring 

 action of the surf. A favorable beach was selected and the vessel carefully beached 

 in such a manner that the surf, loaded with sand and broken shells, would scour the 

 sides of the vessel and rid it of its fouling materials. Other vessels were run into 

 fresh water at frequent intervals (a method still employed to a limited extent) and 

 the organisms normally living in salt water would die and in some instances fall off, 

 thus ridding the hull of its fouling. More recently the vessels were beached at 

 flood tide and, allowing the vessel to list as the tide ebbed, were cleaned as the water 

 would leave the vessel high and dry. 



It has been the goal all along, however, to prevent the attachment of these 

 organisms. That many people have been interested in this problem is indicated by 

 the fact that in England, previous to 1865, according to Young (1867), more than 300 

 patents had been issued for antifouling materials; while in America 166 patents were 

 issued prior to 1922, as found by Gardner (1922). The following quotation from his 

 paper (p. 43) will serve to give some idea of the great variety of materials that have 

 been employed within the last century. 



Amongst the many materials for prevention of fouling and corrosion of iron ships which have 

 had patents taken for their use or been experimented with will be found silicates, quicksilver, 

 plumbago, gutta percha, asphalte, shellac, guano, cow dung; now comes a powerful compound 

 consisting of "clay, fat, sawdust, hair, glue, oil, logwood, soot, etc.," mLxed, "to be plastered on the 

 ships' bottoms"; then we have "emery, shellac, and castor oil"; next "pitch, tar, and shellac"; 

 nest comes another peculiar mixture, "baryta, litharge, arsenious acid, asphaltum, oxide calcium, 

 and creosote"; than another, "Burgundy red earth, grease, lime, unburnt earthenware, chalk, or 

 Roman cement." Next follows a very curious composition consisting of "grease from boiled bones, 

 kitchen stuff, and butter without salt, mixed with poisonous materials." Now we have the grand 

 chef-d'oevre of the whole, which is described thus: "Sugar, muriate of zinc and copper, and the sirup 

 of potatoes or sugar with powdered marble quartz or feldspar." The last one, which will be noticed 

 consists of "asafoetida with pitch, tar resin, and turpentine smeared over the bottom, and then 

 coated with paper or cloth." Who will say, after this, that poisoning and physicking have not had 

 their fair chance? 



More modern methods, however, have centered around the idea of poison 

 paints, for with the advent of iron ships the use of metals as sheathing was rendered 

 impossible because of the electrolytic action in sea water and the consequent dis- 

 integration of the iron of the ship. Many types of antifouling paints containing 

 posions are offered under various trade names, but none has yet been found which is 

 satisfactory under all conditions. Indicative of the types of many of these paints 

 are the two following, used by the Navy as its standard antifouling compositions in 

 1922 and 1925, respectively: 



