FOULING OF SHIPS' BOTTOMS 



197 



1922 NAVT STANDARD ANTIFOULING PAINT 1925 NAVY STANDARD ANTIFODUNG PAINT 



(Per gallon of paint) 



2,248 cubic centimeters denatured ethyl 



alcohol. 

 355 cubic centimeters pine tar oil. 

 355 cubic centimeters turpentine. 

 680 grams gum shellac. 

 680 grams zinc oxide, dry. 

 680 grams iron oxide. 

 336 grams mercuric oxide. 



(Per gallon of paint) 



1,196 grams mineral spirits. 

 306 grams pine oil. 

 564 grams coal tar. 

 923 grams resin. 

 923 grams zinc oxide. 

 616 grams iron oxide. 

 410 grams mercuric oxide. 

 515 grams cuprous oxide. 

 329 grams silica. 



Even before the use of steel ships, methods employed to limit the extent of foul- 

 ing made use of various paints, many of which contained copper and mercury as 

 poisons. In reviewing the methods followed until recently for the prevention of 

 fouling one can not but be impressed with the fact that these methods have been 

 governed largely by haphazard experiment and rule-of-thumb procedure. Pre- 

 cedence apparently has been relied upon more than any analysis of the factors 

 involved. Progress under these conditions naturally is a matter of tardy develop- 

 ment and slow improvement. Consequently, in an attempt to obtain more efficient 

 paints the United States Navy has xmdertaken an extensive investigation of the 

 entire problem, using a great variety of posions in as many paints. It was soon 

 realized, however, that a careful study of the organisms responsible for the foul 

 condition would be of considerable value, and at the request of the Navy Depart- 

 ment, and with its support, this investigation of the fouling agencies has been made 

 under the direction of the United States Bureau of Fisheries. 



Although foul conditions on the bottoms of ships have been studied for many 

 years, such studies have related almost entirely to the effects of fouling and to means 

 of preventing it. Thus we find treatises such as that by Young (1867) on "The 

 Fouling and Corrosion of Iron Ships," and many articles, from time to time, in 

 transactions of such organizations as the British Institute of Naval Architecture and 

 the American Society of Naval Architects and Marine Engineers. One of the most 

 recent and comprehensive of such papers is entitled, "Notes on Fouling of Ships' 

 Bottoms, and the Eflfect on Fuel Consumption," by Capt. Henry Williams, C. C, 

 U. S. N. (1923). Many articles dealing with the effect of fouling, especially with its 

 relation to resistance, have appeared in these journals (McEntee, 1915), but these 

 have not concerned the nature or extent of fouUng. 



The growths on the bottoms of ships have been studied by many naturalists 

 interested in collecting rare species of organisms and in systematic studies of various 

 groups of animals and plants. Thus, Charles Darwia (1853) and H. Pilsbury (1916), 

 in their respective treatises on barnacles, both record many of their specimens as 

 having been secured from ships' bottoms. 



At the time this investigation was begun (September, 1922) no study was 

 known that dealt with the nature and extent of these growths. Since that date, 

 however, two articles by Hentschel, working at Hamburg, have appeared, which 



