Under conditions in Jeffries' era, that was a very fast 100! I'm impressed by his speed. Thanks for this post, and the kink, Mendoza!
Welcome. Back in those days, the shoes for running were suspect, and there were no starting blocks to explode out of the gate. You had to dig your own hole. That makes the times even more impressive. As for other events such the high bar, your feet had to clear the bar, the back flop technique had not been invented.
I just realized I hit the "k" instead of the "l" next to it. I meant LINK of course. One of those funny typos, though. Hahaha.
For the record, 10.2 for 100yards is roughly the equivalent of 11.15 for 100 metres. Measured and timed correctly it was very impressive for the period.