individuality of its creator, and along those lines that repeated experiences have found necessary, to insure success.

In inventing and designing a new machine, one must first thoroughly familiarize himself with its desired performance, as the success or failure of his mechanical creation depends on how nearly perfect that performance is, compared to established or desired standards; and the performance of that machine when made will truly denote how well its designer understood it, and his skill in mechanical manipulation to produce it.

THE STEPS BY WHICH HE IS REQUIRED TO CLIMB AND MOUNT THAT DESIRED EMINENCE

Another important item of calculation must be the relative value of the probable production of the machine, its quantity and quality, to the cost of the machine.

Careful consideration must be given to the working conditions the machine will have to be adapted to. These must include a careful study of the substance to be worked upon in the machine, its regularity or irregularity in shape, its constant or changing conditions under various environments or seasons, and its general peculiarities.

The cost of manipulating the machine must be considered, that is, the required amount of power for its propulsion, and the cost of maintaining its efficient mechanical performance for a certain amount of production, or its durability, and its proneness to get out of order. Nor must one fail to take into account the required intelligence and skill to operate it.

While constantly and carefully bearing in mind the before-mentioned objective points, the prospective successful inventor in designing his machine, must carefully aim for cheapness of construction, which can only be properly accomplished by designing the various mechanical performances of the machine with the least number of parts, and of the simplest form, requiring for their proper production the least amount and cheapest kind of labor in the Pattern Shop, Foundry, and Machine Shop, and, next to the creating of efficient and durable machines, the greatest order of skill in a machine designer is required in producing simple and cheap mechanical designs.

And yet this is not all that is required from him, even in the mechanical line, but he must have such mechanical movements and parts in his machine, as will enable him to secure a good patent on it, which will insure him protection, at the same time carefully and absolutely avoiding any possible infringement on others. In a measure that can be avoided by looking up the copies of patents of similar inventions.

Another important factor in determining the general design of a machine, is the probable market for the same, as that must, in a great measure, decide the justifiable expenditure for the initial or first general cost, for bringing the successful machine into being.

INVENTORS SELDOM HAVE ANYTHING OUTSIDE OF THEIR ASPIRATIONS AND PROSPECTS.

So much for the mechanical or engineering part of the invention.

The next important part is the financial side of it. The estimate for this must necessarily vary with the intended mode of disposal of the prospective invention after its perfection.

If it is the intention of the inventor to dispose of his invention after it is perfected, the expense can be approximately estimated, and in many cases will be moderate, of course varying with the nature of the invention. But if it is the intention to manufacture it, create and supply a market for it, the required capital will always be considerable.

For many obvious reasons, it is considered advantageous for the profitable exploitation of an invention to have the financial end of it under a separate head, which is generally the case. Usually this is "making a virtue of necessity," as inventors seldom have anything outside of their "aspirations and prospects," whether it is that "necessity is the mother of invention," or that "Invention is the mother of necessity," is something that physiologists have not quite determined. But in any event, the prospective successful inventor must provide himself with a "finance minister," variously designated as "Angel," "Backer," or "Octopus."

This part of the inventive problem, to many an inventor, is insolvable for many reasons. To solve it successfully requires good insight, and judgment of human nature. Ability to impart one's own "enthusiastic aspirations," and to keep it up, requires diplomacy and tact.

FINANCE MINISTERS.

But solve the problem he must if the inventor wants to be successful, and various means have been employed to do so. One of them, which is probably as good as any, is for the enterprising inventor to divide that part of his problem into two or several parts. If he cannot command a large amount at once, he will devote his energies to interesting successively small amounts, which will enable him to carry on the development of his invention from one stage to another; each time advancing it further, becoming stronger, and showing enhanced prospects. To sell to each successive "Backer" the interest of his predecessor, and if the predecessor's money has been used to good advantage, that can be done profitably, and to the satisfaction of everybody concerned, as well as increasing the available means for carrying on the exploitation of the invention.

That is one of the ways by which an inventor can provide himself steadily with some one to take care of the "finance portfolio" in his cabinet.

Another, but far more hazardous way, is to resort to the professional promoter.

Great care, however, must be taken by the inventor in these various financial transactions, which necessarily include the making and signing of various contracts and legal instruments, that his entire invention as well as himself are not entirely absorbed by others.

As competent and reliable legal advice may not always be within his reach, he must be able to make contracts advantageously, and above all to be the possessor of a vision sufficiently penetrating to detect "the nigger in the woodpile," in any paper before he signs it.

The value and success of an invention depends upon its demonstrated usefulness to those for whose use it is intended, and their desire to avail themselves of the same.

It very often devolves on the inventor to give that value to it, a task which will not be found easy, especially to the novice.

The first necessary steps to force an invention into the market is to procure as many representative references from people using his invention as