214 NATIONAL ACADEMY OF SCIENCES 



United States Navy has conducted experiments with paints. 

 Prior to that time commercial brands of paints were adopted, 

 and when a vessel was painted with a particular kind that kind 

 was ever afterwards used for the same vessel. This practice 

 proved both inconvenient and expensive, and in 1906 the Navy 

 Department began a series of experiments to determine what 

 mixtures were most effective to prevent corrosion and fouling. 

 The experiments resulted in the adoption of a paint, known in 

 the service as the " Norfolk paint," for practically all vessels 

 of the navy, two formulas being used, one for an anticorrosive 

 paint and the other for an antifouling paint. Mr. Williams 

 remarks : 



" Estimates made in 1910 of the cost of paint for the bottoms of all vessels on 

 the navy list, using the kinds of proprietary brands of paint that were purchased 

 usually prior to 1908 and distributed among the ships in the proportions of each 

 brand then customary and at the prices then current, show that the cost of paint 

 for a single painting of the bottoms of all vessels of the navy, not including coal 

 barges, etc., under the conditions noted, would have been somewhat more than 

 $iCX3,ooo. The cost of an equal amount of the Norfolk ship's bottom paint at the 

 prevailing cost of manufacture would be less than $33,000. As a majority of the 

 vessels of the navy are painted twice a year, it will be seen that the annual saving 

 to the government by this means at the present time is probably not less than 

 $100,000 annually. It should be noted, however, that largely as a result of the 

 government entering the field with its own paint the prices asked for ship's 

 bottom paint by various firms previously supplying the navy has been so reduced 

 that if, for expediency or for some other reason, the Navy Department decided in 

 the future to purchase all or a portion of its ship's bottom paint, there still would 

 remain an appreciable saving to be credited to the Norfolk paint." ^° 



He further remarks on this subject: 



" The question of protecting the underwater bodies of sea-going ships always 

 has been vital, and since the use of steel for hulls has become general, a suitable 

 paint for this purpose has been in demand. Various manufacturers ofifer com- 

 merically, generally under proprietary names, so-called ship's bottom paints or 

 compositions, which are designed to effect the double purpose of protecting the 

 bottom plating from the corrosive action of sea-water and, also, of preventing the 

 attaching of the various marine growths, such as grass, barnacles, hydroids, etc. 

 The necessity for the periodic docking of ships, often at intervals of less than 



^'Engineering News, vol. 66, no. 5, August 3, 1911, p. 138. 



