It is unclear what advancement or innovation in tarpaulin technology Ehmke may have developed. In fact, the Pittsburgh Pirates purchased a tarpaulin to cover their infield in 1908. That tarpaulin, which was laid over the field using a truck took 15 or 20 minutes to install and the same amount of time to remove, was manufactured by the Pittsburg Waterproof Company. An article announcing the innovation is found here.