I've chosen another doubleheader for this post, this one played in Cincinnati. It was a fairly ordinary twin bill, in a fairly ordinary season -- the Cubs finished 68-86, their worst mark in 17 years. They won the first game 10-8 in 18 innings, then lost the nightcap 2-1, and therein lies the tale, as reported by Edward Burns in the Tribune:
The Cubs were declared 1O to 8 victors over the Cincinnati Reds shortly before 7:3O o'clock this evening after 18 arduous innings of the first game of a double header which started at 1:3O o'clock and was interrupted one hour in the 13th inning by the weather man. The teams then started the second game at 7:4O o'clock, a bobtailed affair which was called because of darkness. It resulted in a 2 to 1 victory for the Reds after 4½ innings of play which carried the afternoon's program to 8:41 o'clock.
Now what do you notice in that paragraph that's unusual? First, there's the archaic usage of "o'clock" -- we wouldn't write "8:41 o'clock" today. Incidentally, 8:41 was precisely the time of clock sunset in Cincinnati on August 9, 1942.
This is a little-remembered part of baseball history from that era. The very first night game in major-league history was played in Cincinnati May 24, 1935 -- more than seven years before this date. In those days, though, night games were still comparatively rare:
it was agreed that each team would be granted fourteen night games with one exception in Washington who was granted twenty-one.
More important, though, was the fact that teams in general did not turn on lights to finish games that had been started during daylight hours. There was no specific rule mandating this, it was simply customary in the early days of night baseball. Thus you had the scenario, played out here, of a game being called for darkness in a stadium where they had lights.
Here's the full 1942 Wrigley scorecard; click on it to open a larger version in a new browser window or tab.