268 TOWERS AND TANKS FOR WATER-WORKS. 



mechanics should be employed ; in the long run, besides their 

 ability to spread a smooth and regular coat, their experience 

 will save sufficient material, or make the same material go 

 enough further, to warrant the employment of the skilled me- 

 chanic, if the selection of the individual is put upon a basis 

 of first cost, rather than of comparative excellence. 



Repainting. Intelligent and systematic care should be 

 given a structure continuously after painting, remembering 

 that "an ounce of prevention is worth a pound of cure." 

 Repainting should not be too long delayed, and at the first 

 evidence of this necessity, the old paint should be carefully 

 removed before the fresh covering is applied. In doing this, 

 a strong caustic solution should be used to partially decom- 

 pose the old film, and steel scrapers and wire brushes then 

 employed to detach the coat. Immediately afterward, the 

 metallic surface should be carefully washed down with water 

 and dried, any deep-seated rust-spots or paint which it has 

 been impossible to remove otherwise being burned away by 

 the application of the flame from a painter's torch. 



It stands to reason that the more care exercised in clean- 

 ing down to the metal, the better the results from the new 

 paint coating to be applied, and the greater logevity of the 

 metal. 



In view of the constantly widening range of the use of steel 

 for structural purposes, it is not surprising that constant effort 

 should be directed toward determining the best protective coating 

 for iron and steel. At a recent meeting of the Am. Soc. for Test- 

 ing Materials, a committee report of much importance, presented 

 by its chairman, Mr. S. S. Voorhees, is as follows: 



" PROTECTIVE COATINGS FOR IRON AND STEEL. 



" The membership of the committee has been increased from 

 the original 6 to 17 members, and the committee has aimed to 



