Based on the photo and the description of Yale placing the ball on the ground before the goal-from-field during open play, I assume they were playing with a round soccer like ball.
I also read years ago that pre-1876, a goal from the field (field goal) wasn't even permitted, that the try-at-goal after a touchdown was the only way to score, though I haven't found much else about this since the rules during that era are murky.
Based on the photo and the description of Yale placing the ball on the ground before the goal-from-field during open play, I assume they were playing with a round soccer like ball.
I also read years ago that pre-1876, a goal from the field (field goal) wasn't even permitted, that the try-at-goal after a touchdown was the only way to score, though I haven't found much else about this since the rules during that era are murky.