This is the practice in making material machines in manufacturing establishments--and no other practice there could be successfully pursued.

It is the outcome of the experience of tens of thousands of men for many years--and the result of the expenditure of tons of money.
This remark as to manufacturing establishments does not include the development of new ideas, for which experimentation or original research is needed; because it is sometimes necessary, when venturing into untrodden fields, to test out by mere trial and error certain parts or features before determining enough of their details to warrant incorporating them in the drawing of the whole machine.
Similarly, some experiments must be made in the methods, organization, and material of the naval machine; but in this, case, as in the case of manufacturing establishments, the experimental work, no matter how promising or alluring, must be recognized as of unproved and doubtful value; and no scheme, plan, or doctrine must be incorporated in the naval machine, or allowed to pose as otherwise than experimental, until successful trials shall have put it beyond the experimental stage.
The naval machine consists obviously of two parts, the personnel and the material; these two parts being independent, and yet mutually dependent, like the parts of any other organism.

Obviously, the parts are mutually dependent not only in the quantitative sense that the more numerous the material parts the more numerous must be the personnel to operate them, but also in the qualitative sense that the various kinds of material determine the various kinds of personnel that must be provided to operate them with success.
Gunners are needed to handle guns, and engineers to handle engines.
In this respect, personnel follows material.

In the galley days only two kinds of personnel were needed--sailors to handle the galleys (most of these being men merely to pull on oars)--and soldiers to fight, when the galleys got alongside of the enemy.

Ship organization remained in a condition of great simplicity until our Civil War; for the main effort was to handle the ships by means of their sails, the handling of the simple battery being a very easy matter.