354 
VOYAGE OF THE POTOMAC. 
[May, 
paintings, though they cannot draw, having no idea of perspective. 
Our party saw an excellent likeness of Stewart's "Washington, 
most faithfully copied by a Chinese ; indeed, with a good copy 
before them, they can execute in a masterly manner. In tailoring 
they are equally correct. One of the middies sent a pair of 
pantaloons as a pattern, to have a dozen made by ; each pair that 
was returned came true to the pattern, even to a patch on the seat, 
and a button wanting ! 
They are said to be very acute accountants, and their method of 
computing is certainly singular. The process is by a kind of 
abacus, which they call swan-pwan, or counting boards ; which 
consists of a frame of wood, of various sizes, divided into two 
unequal compartments, by a bar placed crosswise at about one 
third the length from the top. Through the bar at right angles 
are inserted a number of parallel wires, and on each wire in the 
lower compartment are five moveable balls, and in the upper two : 
these wires may be considered as the ascending or descending 
powers of a numeration table, proceeding in a decimal proportion ; 
so that if a ball on any of the wires in the larger compartment 
be placed against the middle part and called unit, or one, a ball on 
the next wire above it will represent ten, and one on the next one 
hundred : so also a ball on the next wire below that representing 
units will be one tenth, next lower one hundredth, and the ball on 
the corresponding wires in the smaller compartment will in the 
.same manner represent five, fifty, five hundred ; ten, tenths, five 
hundredths, &Cc., the value or power of each of these in the 
smaller division being always five times as much as those in the 
larger. It is wonderful the facility with which they will calcu- 
late by this process, and what is remarkable, they are scarcely 
ever known to be wrong, even in the most complicated accounts. 
The city of Canton, as before stated, our officers were not per- 
mitted to enter, as no foreigners are. But the Chinese Reposi- 
tory, an English magazine, published in the suburbs, contains 
many interesting facts respecting the interior of this ancient city, 
from which the following have been taken : — . 
" That part of the city which is surrounded by a wall, is built 
nearly in the form of a square, and is divided by a wall running 
from east to west in two parts. Thei northern, which is much the 
largest part, is called the old city ; the southern part is called the 
