128 INTRODUCTION. 
tific theory, but is now generally approved and adopted; and a system of 
rotation, in which crops cultivated with the hoe, alternate with the grains, has 
been recently found an economical substitute for the former process of summer- 
fallowing. A great advance in farming has been effected by the introduction of 
root crops into field culture. It is true that the labor of cultivation is expensive, 
but it is abundantly repaid by increased production, and the superior condition in 
which the soil is preserved. Our farmers have generally been very negligent in 
regard to improving the breed of domestic animals. Recently, however, the 
efforts of a few public spirited persons in introducing cattle, swine and sheep 
from improved stocks in Europe, have been crowned with high success. The 
race of horses’ has been less improved. It is to be hoped that the time has passed 
when efforts in this important department of agriculture must encounter popular 
prejudice and ridicule. In England the advance in weight of cattle, sheep and 
lambs, has averaged at the Smithfield market, as estimated by different indivi- 
duals, at different times, as follows: In 1810, cattle, twenty-six stone six pounds; 
1830, thirty-nine stone four pounds; 1840, forty-six stone twelve pounds: in 
1810, sheep and lambs, two stone; 1830, three stone eight pounds; 1840, six 
stone six pounds. Although it cannot be aflirmed that an equal advance has 
been made here, yet very beneficial effects have resulted as well from the greater 
care practised in feeding and raising stock, as from the introduction of improved 
breeds from abroad. The merino blood in sheep has been so extensively diffused 
since its introduction here in 1809, that it is supposed none of the former race 
of that animal remains unmixed in the country. Among the animals which have 
been introduced, are the Short horns, Hereford, Devon and Ayshire cattle ; the 
South down, Leicester and Coteswold sheep; the Berkshire, Irish grazier and 
Kenilworth swine; and pure bloods or crosses of some of these animals are 
found in every county, if not in every town in the state. At the present time, 
thirty-five bushels of wheat per acre is not considered a great crop, and the pro- 
duct frequently reaches forty and even fifty bushels. Seventy-five or eighty 
bushels of corn per acre is not an extraordinary yield. We cannot speak with 
