252 TOWERS AND TANKS FOR WATER- WORKS. 



this scale off, so the finished plate comes with no scale upon it 

 to the cooling-beds. In the rolling of angles and similar 

 shapes it is not possible to do this. Therefore, there is more 

 scale upon the angles than on plates. After rolling, shapes 

 are as a rule stacked immediately upon loading-beds prepara- 

 tory to shipment, it being against the mill's policy to hold 

 material any longer than it is necessary to get cars and to 

 load. Shapes after they come from the strengthening-press, 

 which is directly after cooling, are not under cover. In case 

 of plates, the conditions are different. After the plates are 

 rolled they have to be laid off and sheared to size, and then 

 stacked up awaiting shipment. In the majority of cases this 

 is always under cover. Open cars are nearly always used in 

 shipping steel, on account of the convenience in loading from 

 cranes and also on account of the variation in lengths." The 

 above explains the processes and evolution at the mills, and in 

 order to arrive at the condition at which the material reaches 

 the shops, inquiry was made of a large boiler and metal-work- 

 ing establishment, located from 600 to 700 miles from the 

 point of metal-supply. They write : "We find very little 

 rust, mill-scale, or grease on any of the sheets coming from the 

 mills; though we must confess we find much more now than 

 we used to heretofore. . . . There is a big difference in the 

 steel plate from the different mills; there is a gloss or finish 

 upon some, while from another mill they appear red, as though 

 they were rusted. Now any of these plates will stand the 

 weather without being injured or rusted, especially the ones 

 best finished, and it is not necessary, in our opinion, to paint 

 or oil the plates at the mill. The effect of rolling plates after 

 they were painted would be to scale off much of the paint." 

 From such testimony it appears that, under ordinary circum- 

 stances, it is not necessary to protect plates at the mill by 

 painting or priming, and that at the shop the mechanical 

 work of rolling to radius, as for boiler and stand-pipe plate, 



