[Avodah] Shiur of an Etzbah(finger)

[Zev Sero]

RYGB wrote back on 30-Nov-2001
> <http://www.aishdas.org/avodah/vol08/v08n063.shtml>:
>> Minhag Yerushalayim, which
>> is based on the Rambam's measure of an etzba, which in turn was based,
>> IIRC, on the size of the Egyptian drachma.

The Rambam gave the shiur of a revi'is as 27 dirhams, by which he presumably
meant the Egyptian ones of his day.  But the minhag Y'm, which RACN defended,
was based on the Ottoman dirham, which was about 15% bigger than the Egyptian
one that the Rambam knew, and thus all their shiurim were actually bigger
than the Rambam's, though they probably didn't realise it.  The Rambam's
etzba was thus approximately 19.1 mm rather than the 20 that RACN gives.

-- 
Zev Sero               A citizen may not be required to offer a 'good and
zev at sero.name          substantial reason' why he should be permitted to
                        exercise his rights. The right's existence is all
                        the reason he needs.
                            - Judge Benson E. Legg, Woollard v. Sheridan