as well as does first-class brushwork. Again, spraying is a messy process, and much paint is likely to go to places for which it was not intended. One great advantage which it has is that it will reach locations difficult of access by the brush, and which, in consequence, are often improperly protected. As far as ultimate total cost is concerned, it is probable that the saving in labor will about offset the wastage of paint.

Cleaning of Metalwork for Shop Coat

Unless metalwork is thoroughly cleaned before the shop coat of paint is applied, the endurance of the protection will be short; hence it is truly economic to ensure that the cleaning is effectively done, so as to remove all dirt, rust, scale, and grease. The time elapsing between cleaning and painting should be made as short as possible; because it does not take long to start fresh rusting on cleaned metal. As to the methods for shop-cleaning, hand-work ought to suffice; for sand-blasting should be unnecessary. If the metal is very badly rusted, it generally establishes sound evidence of carelessness on the part of somebody who ought to be held responsible for its injured condition.

Strictly speaking, all rolled material for bridgework should be taken from the mill to the shops with the least possible delay, and should be stored under proper shelter from the elements, in order to avoid rusting; and it would be in the line of true ultimate economy to give it a coat of linseed oil soon after it comes from the rolls. Most steel manufacturers and users will claim that these precautions are unnecessary, that the coat of oil would be troublesome to put on, and that the storage sheds would cost a lot of money. These objections, of course, are important; but the author is of the opinion that, in the interest of true economy, they will ultimately be overcome, and that sometime in the future all proper precautions will be taken on important steel structures to protect effectively against rust the metal that is to be employed in their manufacture.

The torch should first be used freely in cleaning metal in the shops, for the double purpose of burning any grease that there may be on it and to remove all moisture; after which should follow scraping with steel brushes, file scrapers, and putty knives. Any heavy seed rust which has formed cups in the metal should be chipped out by hammer, care being taken to avoid all unnecessary cutting of the steel. This cleaning should be most carefully watched by a competent and reliable inspector whose compensation comes wholly from the owner; but too often it is done in a careless or perfunctory manner by ignorant foreigners who take no interest in performing their work well. It used to be the custom in some bridge shops to turn over the painting to newly-imported Hungarians, who were the cheapest laborers on the payroll; and, as a result, the author has seen metal delivered  at  site  with  the  shop  coat  of  paint  overlying  in  large  areas  half  an  inch  of  frozen  mud.  Conditions  in  this  respect  today  are  undoubt-