Law Of Averages
‘Catacombs Are Four Cubits Long’
(Bava Basra 100b)
Our sugya rules that a laborer hired to dig a grave must dig a pit four cubits long. The Rashbam (s.v. “Veha’kuchin…”) and Ramban maintain that four cubits is sufficient to bury someone of average height (three cubits) and provide for the miscellaneous needs of any burial. Tosafos (s.v. “Vehakuchin…” and on other Talmudic passages) contends that an average person is taller than three cubits. Thus, less than a full cubit remains for the miscellaneous burial needs.
Calculating Halachic Measures
Many poskim assume that there is no disagreement regarding the average height of a person. Rather, the dispute revolves around the measure of a cubit, which consists of six tefachim. The Rashbam maintains that a tefach is 9.6 cm (3.78 inches), but Tosafos maintains that it is only 8 cm (3.15 inches).
A cubit then, according to the Rashbam, is 57.6 cm (22.68 inches), and three cubits (172.8 cm, 68.03 inches) is room enough to bury a person of average height. According to Tosafos, however, a cubit is 48 cm (18.9 inches), and three cubits (144 cm, 56.7 inches) is not sufficient room to bury a person of average height. That’s why Tosafos maintains that the average person is over three cubits tall. He agrees on the objective reality. He just disagrees how this objective reality translates into cubits.
Rabbi Yechiel Michel Epstein, author of Aruch Hashulchan, calculated an average person’s height over 100 years ago to be 160 cm (63 inches). Some people questioned this estimate, but in his Midos Veshiurei Torah, Rabbi Chaim P. Benish records that a survey of 4,229 Polish and Russian Jews showed the person’s average height to be nearly identical: 161.2 cm.
An important application of this topic concerns the proper height of a mechitzah, which is supposed to prevent the men on one side from seeing the women on the other. Many halachic authorities rely on our sugya to determine the average person’s height. It’s possible, though, that the height of a mechitzah is dependent on the height of the people in the shul (see Responsa Igros Moshe, Orach Chayyim 1:39; Orach Chayyim 4:29; Orach Chayyim 3:23-24; Responsa Minchas Yitzchak 2:20; and Responsa Mishneh Halachos 7:12 among others).