Page 85 - Records of Bahrain (3) (ii)_Neat

The pre-war economy: pearl fishing, 1899-1915 501

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Cliau. The unit in the dealer's system is called a Chau ^ (plural, Achwah
) ; and it should be clearly understood that this Chau, though
derived from a.weight, is not itself a weight. Chaus are of 4 kinds,
obtained by an identical process from the 4 different Mithqals which
follow :—
Bahrain Mitbq&l * = 160 grains Troy.
Qatar do./1 =100 do. do.
Bombay do. =74 do. do.
Poona do. =08* do. do.

In each case the number of. Chaus in a pearl is found by squaring the
weight (in Mithqals) of the pearl and multiplying the result by 330.
Thus let c be the number- of Chaus and m the number of Mithqals, then
c=w* x 330
and the result (c) will be in Bahrain, Qatar, Bombay or Poona Chaus
according as the weight of the pearl was expressed ill Bahrain, Qatar,
Bombay or Poona Mithqals. One Bahrain Chau, it should be observed
is approximately equal to 4 Bombay Chaus ; for, let m be the weight of
the pearl in Bahrain Mithqals, then its weight in Bombay Mithqals is
yy in, and it follows that the number of Bahrain Chaus in the pearl in
question is to the number of Bombay Chaus in the same as 330m9 is
to 330 x (yy0 in),1 that is as 1 is to 4Tl0. In the same manner it may
be Remonstrated that 1 Qatar Chau represents approximately the same
quantity of pearl substance as 4} Bombay Chaus.
Both Arab and Indian dealers have rules of thumb for the convenient
calculation of Chaus from weights, but both classes have recourse by
preference to ready reckoners in Arabic and Gujarati which are obtainable
from Bombay. The (simplified) Arab rule is : Express the weight of the
pearl in Habbahs (of which there are 60 to the Bahrain or Qatar
Mithqal), square the number of Habbahs, -increase the result by 1 per
cent., and divide by 100.' The (simplified) Indian rule is: Express the
weight of the pearl in Rattis t (of which there are 24 to the Bombay or
Poona Mithqal), square the number of Itattis, multiply by 55 and divide
by 96. Algebraic analysis will show at once that both of these rules are
virtually the fundamental rule
c s=«i* x 380
thrown into a different form.
The Chau, to whichever category belonging, is divisible in the first
instance into 100 Dukralis (plural, Duwakir jSIj* ). In the case
of the Arab Chau each Hukrah is again resolvable into 100 Mazur-
while in the case of the Indian Chau the Dukrah consists of 16 Badams
flixj and the Badam of 16 Yisvnsis .
Rates. "When the number of Chaus in a pearl has been ascertained it only
• remains, in order to determine its value, to apply the market rate per
• These are both exceptional weights and are called SUrati . The
ordinary Bahrain and Qatar Mithqftls (the former called also Mashhad Alithqfil) are
muoh heavier, being equal respectively to 6 and 7 Bombay Mithqals, but they aro not
asod in Chau calculations.
t The Ratti again ia composed of 4 Dfius, tho Dan of 4 Anahs and Iho Anah of 6*}
Dukraha.