"This is the first Portland cement concrete street built in the United States ... Here started the better roads movement which has given our citizens from coast to coast swift and sure transportation."
- Historic marker, Bellefontaine, Ohio, celebrating the 50th anniversary of America's first concrete pavement, 1941
1893
YearAdded:
Image Credit: Public Domain (Author's Choice)Era_date_from: 1893
1976
As one of the large strikes in the Lake Superior geological district, the Chapin Mine was located under a cedar swamp and unminable until it was drained by one of the largest pumping engines of the 1880s. Miners at the Chapin Mine, which began producing ore in 1880, soon tried to sink a deep shaft through 90 feet of quicksand, using enormous pumps driven by compressed air. The sand was frozen using two of the largest refrigeration compressors built, and a sectional cast-iron circular shell lined the D shaft. Mining continued for ten years using conventional pumps to dewater the lower levels.
YearAdded:
Image Credit: Public Domain; Produced prior to 1/1/1923Era_date_from: 1893
1987
Innovations
As one of the large strikes in the Lake Superior geological district, the Chapin Mine was located under a cedar swamp and unminable until it was drained by one of the largest pumping engines of the 1880s. Miners at the Chapin Mine, which began producing ore in 1880, soon tried to sink a deep shaft… Read More
"This is the first Portland cement concrete street built in the United States ... Here started the better roads movement which has given our citizens from coast to coast swift and sure transportation."
- Historic marker, Bellefontaine, Ohio, celebrating the 50th anniversary of…