To "ANSWER INTELLIGENTLY WHAT AND HOW TO INVENT." It is first necessary to analyze most carefully the various phases of invention of various natures.

It will be observed that inventions in general may be divided into several divisions, as follows:

First:—Fundamental physical principles, which are very rare and purely scientific.

Second:—Basic mechanical adaptation to and for the first division which generally comes into existence soon after the discovery of the first.

Third:—Basic mechanical adaptation to a well-defined production, substituting human or animal exertions; which comes by degrees, and none too often.

Fourth:—Improved mechanical applications.

Fifth:—Diverse or varied mechanical applications.

The last two are the most prolific or numerous classes. The first division includes our physical sciences. The second is the first mechanical harness for utilizing a new discovery in the laws of physics for different purposes. The third includes the first mechanical appliances receiving impulse from some other body for doing to greater advantage that which is done by direct human or animal exertions, and are commonly termed labor-saving machines.

The fourth are the continuous improvements on the third, and may include basic mechanical contrivances.

The fifth is for accomplishing the same ends as the Second, Third and Fourth, but also for the greater adaptability for certain specific purposes, and for popularizing its production; that is to prevent the exclusive monopolizing of certain advantages gained through and by the Second and Third.