quarter of a century ago the author used to employ the last-mentioned paint as a finishing coat, and found it excellent; but for a shop coat he believes that nothing is as good as truly-first-class, red-lead paints.

Between 1906 and 1912 there was made, on the Havre de Grace, Md., bridge of the Pennsylvania Railroad Company, an elaborate and exceedingly valuable series of tests of nineteen different kinds of paint under the direction of certain expert engineers. The results, as reported, emphasize the fact that red-lead paints and those having a considerable amount of red lead in their composition are the most durable, and that a paint in which the top coat is strictly a preservative cover over the red-lead coat gives the best results of all, and justifies the well-known philosophy of the late Mr. Houston Lowe regarding protective paints for steel.

To quote the exact words of Mr. Geo. S. Rice, one of the engineers who reported on the said tests, "this philosophy prescribes the production of a solid and sufficiently-elastic foundation with rust-restraining properties by a priming coat of red lead, followed by a transition coat intermediate between the primer and the top coat, the office of the latter being essentially protective of the undercoats."

It was noticeable in the test that the paints which withstood best had in all instances a very large percentage of pigment in their composition.

The winning paint in the competition was a combination of the kind just described, submitted by the Lowe Brothers Company.*

In his book "Paint for Steel Structures" Mr. Lowe expresses these conclusions:

1. That the priming, or first coat of paint, upon any surface is the most important one; and that it should form an inhibitive, firm, unyielding, and receptive foundation for those to follow it.

2. That under-coats should dry harder and more quickly than those above them, and that the difference in drying between adjoining coats should not be very great.

3. That the quality of the binder is equally as important as the quality of the pigment.

4. That the quantity or weight of pigment used is equally as important as its quality or volume.

5. That the time and method of application are equally as important as the quality of the paint.

There used to be some well-founded objections to red-lead paints in general, and these still hold good against the cheap varieties thereof. The principal ones were a tendency to sag and run on vertical surfaces, and

* This statement is on the authority of Lowe Brothers' written claim, but it has been contradicted by Dr. Sabin, who says that the winning paint was a pure red lead manufactured by the National Lead Company. Dr. Sabin prefers to use red-lead paint for all three coats instead of for the shop coat only, in spite of the very prevalent idea that red lead, for efficiency, should be covered by a more elastic pigment.