British Association for the Advancement of Science. 279 
derangement of the currency in the commercial cities of America, 
English goods were sacrificed at ruinous prices. In the mean time, 
the commercial distress which had visited our own country was 
passing away, and an effective demand for our products had arisen 
from other quarters, as appeared from the fact, that although the 
real value of British goods exported to the United States, which, 
on the average of the five preceding years, was near £9,000,000, 
fell in 1820 to £3,875,286, the general exports from the United 
Kingdom to foreign countries were greater in 1820 than they had 
been in the preceding year. 
In 1830, the date of the last census, the population of the United 
States was 12,867,165, and the official value of the trade with this 
country £16,292,637. The increase, as compared with 1790, was 
227 per cent. on the population, and 252 per cent. on the amount 
of trade. If the comparison is made with the remaining decennary 
periods, it will be found that the increase in 1830 was as follows: 
Increase per “wet 
Population. ade. 
Compared with 1800 -— - L  emae pan s 
7 eds i pa = T14 {Oo 9g ae 
“ ii4 1820 es bi 334 = a 115 
The increase of population in the United States, between 1820 
and 1830, was at the rate of 34 per cent. per annum.” If we as- 
sume that the increase has since gone forward at the rate of 3 per 
cent. in each year, the number of American citizens in 1835 must 
have been 14,784,589. The official value of their trade with this 
country in that year was £25,671,602. A comparison of this 
amount with the value of the trade in the years of the different enu- 
merations, exhibits the following results :— 
Increase per cent. 
Population Trad 
Compared with 1790 -  - 276 - = 455 
vs “« 1800 - - 178 - - 177 
« 1 BIO i= - 104 - - 146 
' aie i>) | yee - 53 - - 239 
4 adeeb: * al pra? « - - 57 
But Mr. Porter considered that it was not simply with reference 
to the numerical increase of the citizens of the United States that 
we should consider this question of the increase of our trade. Dur- 
ing the forty seven years that have elapsed since the first census 
was taken, in 1690, at least 11,000,000 of inhabitants have been 
