One thing leads to another in genealogy.
I was researching an uncle (by marriage), Waino Aleksanteri Seppelin, who came to this country from Finland in 1910 and very shortly got a job as a laborer in a steel mill in Warren, Trumbull, Ohio, USA.
Waino eventually worked into the better-paying job of “heater.” His census entries in 1920, 1930, and 1940 listed that he performed that job in a steel mill. Under the occupation columns for these three censuses, there were code numbers penciled in for Waino. What did they mean?
It was time for some searching on Google. I entered “definition of occupation of heater in steel mill” in the search window and found results for all three censuses. Not surprising, each of the entries had its origins in the U. S. Census Bureau.
The 1940 resource that I found was a PDF of a booklet entitled Occupation and Industry Classifications and Instructions for Using the Occupation Index. I found it here. I scrolled through the pages to find the number code 446 29 that was penciled in next to Waino’s occupation. Sure enough, there was the occupation “Heaters, Metal.”
The 1930 resource that I found was another PDF entitled 1930 Census: Alphabetical index of occupations. I found it here. In this case, I looked for the code 1724 that was penciled in Waino’s census entry. That was a reference to the occupation of Heater in various types of metal mills, including rod mill, rolling mill, sheet mill, soaking pit, and tube mill. Since I knew that Waino worked at mills making sheets from thicker steel forms, I concluded that the reference to sheet mill was the most appropriate.
Going back to the 1920 census, the coding was less sophisticated. My Google search led me to the website for IPUMS USA with a page entitled “1920 Occupation Codes.” The home page explained “IPUMS USA collects, preserves and harmonizes U.S. census microdata and provides easy access to this data with enhanced documentation. Data includes decennial censuses from 1790 to 2010 and American Community Surveys (ACS) from 2000 to the present.” It sounds like IPUMS might be useful in other genealogical research situations.
In this case, the occupation code penciled in on Waino’s census entry was simply 182. It was included under a heading of “Furnace Men, Smelter Men, Heaters, Pourers, etc.:” the entry “Heaters.”
I had to dredge up some of the knowledge I gained from my college education and from my professional experience as the editor of Metalproducing magazine (Also known as 33 Metal Producing, now defunct and available only in libraries. Check WorldCat for availability) to remember that a heater was the guy who was replacing slabs of steel in a heating furnace to bring them up to the required temperature for rolling into thinner cross-sections that became sheet steel.