"The typical hive of America is the improved Langstroth, which has no other covering for the frame tops but a flat roof-board allowing 1/4 in. space between the roof and top-bars for bees to pass from frame to frame." — The Encyclopedia Britannica, 1910

Langstroth Hive

"The typical hive of America is the improved Langstroth, which has no other covering for the frame tops…