USES TO WHICH IRON IS PUT 133 



production, and wire rod production was al^out one seventh 

 of the i)i(\scnl. The country was then ini})ortin<!: lieavil\' 

 of wii'e rods, and was importing all of its tin plates, included 

 in the above table of current production inider plates and 

 sheets. Even wdth these imports, however, the consumption 

 of sheets, ])Iates and wire rods was, relative to the total, 

 much le.^s than at present. 



Out of the total production of 3,200,000 tons of plates 

 and sheets, about two fifths is Xo. 16 gauge (one-sixteenth 

 inch thick) and thinner, the balance being thicker and running 

 up to very heavy plates. The former is known by the gen- 

 eric term of sheets, but this category includes the sheets 

 from w^hich tin plates are made, the technical term for the 

 sheet before it is coated with tin being black plate. About 

 Iialf a million tons of tin plate are made annually, the tin coat- 

 ing constituting an average of about 2 percent of the total 

 weight. Fifteen years ago no tin plate \vas made in the United 

 States, and the demand w^as supplied by imports, but the 

 greatest toimage imported was 330,000 tons. It is astonish- 

 ing that so light an article as tin plate should so run into ton- 

 nage, inasmuch as 100 pounds of tin plate of the average 

 thickness will cover an area of 218 square feet, so that a pro- 

 duction of half a million tons w^ould cover an area of 55,000 

 acres, or eighty six square miles, giving thirty square feet to 

 every inhabitant of the country. The ubiquitous tin can 

 for food products explains over half the production; the 

 remainder finds widely varied uses. The amount used in 

 carpet sweepers is not inconsiderable. 



Of sheets lighter than 16 gauge which are not tinned the 

 production exceeds half a million tons. A portion is gal- 

 vanized, a wholly misleading term signifying coating, with 

 spelter (commercial zinc) by dipping in the molten bath. 

 The uses are so varied that even the more important cannot 

 here be given. Perhaps of no other steel product have the 

 uses so increased of late years. In much building lath has 

 given aw^a}^ to expanded metal as a basis for plastering, while 

 the plaster itself has given away to steel sheets stamped in 

 ornamental designs, particularly for ceilings. Factory build- 

 ings are covered with corrugated sheets. In electrical work 



