788 Transactions of the American Institute. 



nothing whatever about enameling glass, and hadn't the faintest 

 conception of the difference between a positive and negative pattern. 

 Another gentleman who seemed to think that he knew a good deal 

 about the relation of things, remarked, "yes, those were very good 

 stencils, they conld be made by rolling." It is barely possible that 

 he would like the job of making a pair of rolls that would roll a plate 

 just like that. To make such a plate as this, costs, perhaps, $10 for 

 a die, with which to cut it. They are made double, male and female ; 

 and then, perhaps, $5 to make the plate. Total cost from $12 to $15 

 for the first plate, and $5, or thereabouts, for each succeeding plate. 

 Now, if that gentleman is present, will he be kind enough to just tell, 

 us how much it would cost to make a pair of rolls that, would turn 

 out a plate thirty-six -inches long by fifteen wide % Then how much 

 would it cost to reduce the plate to a perfect plane, so that when it 

 is laid upon the glass, it would touch at all points ? At the same time 

 the plate must not be distorted. 



An important application of this process would be to enamel iron 

 for buildings. This cost would be little, for the principal labor can 

 be done by boys. An iron building can be enameled for about thirty- 

 five cents per square foot ; and the saving of the expense of painting 

 would pay for that in five or ten years. 



Mr. T. D. Stetson — Can it be done upon either cast iron or wrought 

 iron ? 



Mr. "W. E. Partridge — Either. It will be observed that one diffi- 

 culty in the use of stencil plates is entirely obviated by this process ; 

 which is the necessit} r for breaks in forming letters or other patterns. 

 Here the form is complete with one plate. 



A Member — In enameling an iron building, how would you apply 

 the heat ? 



Mr. "W". E. Partridge — The enamel would be applied to the iron as 

 it came from the foundry. 



Mr. T. D. Stetson — One word with regard to the enameling of 

 iron, and the construction of iron-clad buildings. A building may be 

 of brick, and yet plated or veneered with iron. There were whole 

 blocks of houses made some years ago in that way, not enameled, 

 but so coated as to make a very perfect imitation of brown stone. 

 The operation was briefly this : to take the same kind of varnish 

 used in japanning, having it preferably of a light color approximating 

 to that of brown stone ; put it on thick, by one or more operations, 

 and when the composition is a little sticky, sprinkle upon it some actual 

 brown stone in the form of powder. They will probably endure the 



