Page:Popular Science Monthly Volume 16.djvu/193

 common, inferior result may again be raised to a higher level. Thus, if the present higher races could consent to sacrifice their present superior position for several, perhaps many, generations, it is conceivable that the human race may be again raised, and possibly to a still higher plane. From a lower plane but broader base, it may be possible to build up again to a higher point than any yet reached. Or, to put it differently: the effect of true breeding is doubtless excellent in one direction, and for the perfecting of one or a few qualities, but it tends also to specialize, and therefore to petrify, and thus to prevent indefinite progress. Mixing, on the other hand, it produces a more plastic nature or better clay, a more generalized and therefore a more progressive form—for the line of true progress has ever been through generalized forms. Therefore it may be that, after the best results of true breeding have been attained in the production of the best varieties in several limited directions, then the general mixing of these perfected varieties will produce a generalized human type capable of more universal progress in all directions.

 

HE frequent examination of Maury's charts for the purpose of shortening tedious passages under sail, led to the idea of remodeling them for greater ease of consultation, and at the same time of adding the vast store of data accumulated since their publication.

The first conception of the new charts embraced only their salient features: from time to time, during the progress of the work, various details occurred and were added, so that to-day the undertaking may be said to be systematized, and it is this system which I shall describe.

The sources whence the information for the charts is derived, are two: log-books of ships of our own navy, and journals of merchant-vessels.

On board every vessel of the United States Navy it is obligatory to keep an official daily record, called the log-book. The first part contains full and explicit directions for keeping it; lists of the officers and men composing the ship's company; plans and sections of the ship; a description of the armament, boats, and small-arms; a table of deviations of the compasses; and a description of the meteorological instruments used, their location, and comparisons with standards. Following this matter are blank pages, suitably ruled, for a six months'