Sunday, October 2, 2011

Marriott's Avitor -- October 2, 2011


Frederick Marriott was born in Britain and was a publisher.  He had been a partner in the Aerial Transit Company with Stringfellow and Henson.  After coming to California for the Gold Rush, he founded the long-lived San Francisco News-Letter and built the Avitor Hermes, Jr.  The flight of the Avitor is regarded as the first controlled flight in the United States.  A reproduction of the Avitor is on display at the Hiller Aviation Museum (http://www.hiller.org/).  Sadly, nothing came of the Aerial Steam Navigation Company after the Avitor burned.  This article is from the 31-July-1869 Scientific American.  The illustration is from Aerial Navigation by Arthur de Bausset, 1887.  

Ballooning In California.

In a large hall, near San Francisco, a small steam balloon has lately been tried, with so much success as to excite enthusiasm among the stockholders, and make them think that the great problem of aerial navigation has been solved. We are assured that the first packet of a regular line of aerial steamships will start from California for New York within a very few weeks.

We should be glad if there were any reasonable basis for this expectation, but we find none whatever. Substantially the same forms of balloon and machinery have before been tried, always with apparent success on the small scale in still air; always with failure when subjected to atmospheric currents. Experience shows that the attachment of wings, tails, and wheels to balloons, tends more to impede than to assist their progress.

Aerial navigation will never be reduced to a regular commercial system until some one shows us how to dispense with the unwieldy gas balloon, and replace it with an effective method of generating the requisite buoyant power. The subject is one of great importance, and worthy of diligent study on the part of all inventors. Glorious fame and princely fortune await the successful discoverer.

We copy from the San Francisco Times the following account of the recently tried Aerial Carriage:
"The carriage, which is merely a large working model, is a balloon, shaped like a cigar, both ends coming to a point. It is 37 feet long, 11 feet from top to bottom, and 8 feet in width. These are the measurements at the center of the balloon, from which point it gradually tapers off toward either end. Around the balloon, lengthwise, and a little below the center, is a light framework of wood and cane, strongly wired together and braced. Attached to this frame, and standing up as they approach the front of the carriage, are two wings, one on each side. They are each five feet wide at a little back of the center of the carriage, and do not commence to narrow down until they approach the front, where they come to a point. These wings are made of white cloth fastened to a light framework which is braced securely by wires. The main frame is secured in place by means of strong ribbons, which go over the balloon, and are attached to corresponding portions of the frame on the other side. To the frame at the hind part of the carriage is attached a rudder, or steering gear, which is exactly the shape of the paper used in pin darts, four planes at right angles. This, when raised or lowered, elevates or depresses the head of the carriage when in motion; and when turned from side to side, guides the carriage as a rudder does a boat. At the center and bottom of the balloon is an indentation, or space left in the material of which it is built, in which the engine and machinery are placed on framework.

"The engine and boilers are very diminutive specimens, but they do their work handsomely. The boiler and furnaces together only a little over a foot long, four inches wide, and five or six inches in height. Steam is generated by spirit lamps. The cylinder is two inches in diameter, and has a 3-in. stroke. The crank connects by means of cog wheels, with tumbling rods which lead out to the propellers, one on either side of the carriage. The propellers are each two-bladed, four feet in diameter, and are placed in the framework of the wings. The boiler is made to carry eighty pounds of steam. When not inflated, the carriage weighs eighty-four pounds. The balloon has a capacity of 1,360 feet of gas. When inflated and ready for a flight it is calculated to have the carriage weigh from four to ten pounds.

"An engineer's private trial trip was first made in the presence of the constructing engineers, several of the shareholders of the Aerial Steam Navigation Company, a number of the employees and residents in the neighborhood. The morning was beautiful and still—scarcely a breath of air stirring. The conditions were favorable to success. The gasometer was fully inflated, and the model was floated out of the building. In six minutes steam was got up—the rudder set to give a slight curve to the course of the vessel—and the valves opened. With the first turn of the propellers she rose slowly into the air, gradually increasing her speed until the rate of five miles an hour was attained. The position of the rudder caused her to describe a great circle, around which she passed twice, occupying about five minutes each time. Lines had been fastened to both bow and stern, which were held by two men, who followed her track, and had sufficient ado to keep up with her at a 'dog trot.'

"As she completed describing the second circle, a pull given to the head line, unintentionally, caused the rudder to shift to a fore-and-aft position when the model pursued a straight flight about a quarter of a mile; she was then turned round, and retraced her flight to the point of departure; whence, being guided, she entered the building. The fires were drawn, and the first extensive flight of a vessel for aerial navigation was accomplished. The total distance traversed was a little over a mile. The appearance of the vessel in the air was really beautiful. As seen in the building she looks cumbrous and awkward. The change of appearance as she is circling gracefully through the air, is equal to that of a ship when first seen in the water. The moment of opening the steam valve was one of suspense; as the vessel rose and forged slowly ahead, the suspense was scarcely dissipated; but in a very few seconds her speed increased—in obedience to the rudder she commenced to swing round the curve—the men at the guys broke into a trot, and cheer upon cheer rose from the little group of anxious spectators.

"The public exhibition was attended by some slight accidents, but elicited much enthusiasm from the audience which had assembled in a hall where the trial was made. The wind was so violent and irregular without, that it was considered unsafe to risk the model beyond the shelter. The carriage mounted near to the roof with a firmness and steadiness equal to the movements of an ocean steamer on smooth water. The guests cheered long and loud, and many fairly danced with delight at the success. The trip back and forth across the hall was performed several times with success.

"Within a few weeks the first large vessel will be completed by the Aerial Steam Navigation Company—one calculated to carry four persons—and the principles involved in its construction will then be fully tested. The projectors consider that the model carriage has developed two facts of the greatest importance. First, the effective power developed by the propellers is greater than the estimated power according to the formula; of aero-dynamics; and, second, the atmospheric resistance encountered by the vessel was less than had been calculated. Consequently the speed attained was higher than was estimated, and at the next trial, when the effective heating surface of the boiler will be increased, a further considerable increase of speed will be attained. Some doubt had been entertained as to the facility of steering the vessel. That is shown to be the easiest part of the business. She obeys the deflections of the rudder with extreme sensitiveness, and is under the most complete control."

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