Knowledge of new innovation was spread by several means. Workers who were trained in the technique might move to another employer
or might be poached. A common method was for someone to make a study tour, gathering information where he could. During the
whole of the Industrial Revolution and for the century before, all European countries and America engaged in study-touring;
some nations, like Sweden and France, even trained civil servants or technicians to undertake it as a matter of state policy.
In other countries, notably Britain and America, this practice was carried out by individual manufacturers anxious to improve
their own methods. Study tours were common then, as now, as was the keeping of travel diaries. Records made by industrialists
and technicians of the period are an incomparable source of information about their methods.
Another means for the spread of innovation was by the network of informal philosophical societies—like the Lunar
Society of Birmingham—in which members met to discuss science and often its application to manufacturing. Some of
these societies published volumes of proceedings and transactions, and the London-based Royal Society of Arts published an
illustrated volume of new inventions, as well as papers about them in its annual Transactions.
There were publications describing technology. Encyclopedias such as Harris's Lexicon technicum (1704) and Dr. Abraham
Rees's Cyclopaedia (1802-1819) contain much of value. Cyclopaedia contains an enormous amount of information about the science
and technology of the first half of the Industrial Revolution, very well illustrated by fine engravings. Foreign printed sources
such as the Descriptions des Arts et Métiers and Diderot's Encyclopédie explained foreign methods with fine engraved plates.