In this connection it may "not be amiss" to state that the first person known to have ascended--some eighty years ago, as the "History of Kite Carriage" informs us, "was a Miss"--a young lady of some one hundred and twenty-six pounds, avoirdupois. She was seated in a chair underneath the gigantic structure which weighed nearly thirty pounds, had a surface of about sixty square feet, and rose most majestically to a hight of six hundred feet--an incontrovertible instance of the superior courage of the gentler sex over man. The kite is maintained in the air by two opposing forces: the impelling power of the wind--lifting it by striking against it at an angle, and the restraining powers of the string--motive-force and gravitation combined; so that in the kite, above all, we possess in a crude form, the three principles requisite for artificial flight: the plain, weight and propelling force. By improving upon the kite, therefore, we will arrive at the practical solution of the problem of artificial flight. X.--BALLOONS IMPRACTICABLE. It is not creditable to the present age that the problem of ærial navigation has not been solved. But one of the causes has undoubtedly been the discovery of the balloon, which has retarded this science for nearly a century by misleading men's minds, and causing them to look for a solution of the problem by the aid of a machine lighter than air, and which has no analogue in nature. Weight is one of three essential factors in flight, for a light body cannot be propelled through a heavier one. Hence all attempts at driving and guiding the balloons have signally failed. This arises from the vast extent of surface which it necessarily presents, rendering it a fair conquest to every breeze that blows, and because the power which animates it is a mere lifting power, which acts in a vertical line. The balloon, consequently, rises through the air in opposition to the law of gravity, by which all flying creatures are governed, very much as a dead bird falls downward in accordance with it. Having no hold upon the air, this cannot be employed as a fulcrum for regulating its movements, and hence the cardinal difficulty of ballooning as an art of locomotion and its uncertainty, because the air-currents cannot be regulated. A balloon starting from San Francisco might be intended for New York, but, against the desire of the passengers, alight in China or the Canibal Islands, which would be rather disagreeable.