M. de Fonvielle, possessed of both courage and experience, was prepared to put in practice a method of guiding by a small propelling force a balloon that was being carried by sufficiently favouring winds within a few degrees of its desired goal--and in the case of Paris the goal was an area of some twenty miles in diameter. Within the invested area several attempts were actually made to control balloons by methods of steering. The names of Vert and Dupuy de Lome must here be specially mentioned. The former had elaborated an invention which received much assistance, and was subsequently exhibited at the Crystal Palace. The latter received a grant of L1,600 to perfect a complex machine, having within its gas envelope an air chamber, suggested by the swimming bladder of a fish, having also a sail helm and a propelling screw, to be operated by manual labour.
The relation of this invention to others of similar purpose will be further discussed later on. But an actual trial of a dirigible craft, the design of Admiral Labrousse, was made from the Orleans railway station on January 9th. This machine consisted of a balloon of about the standard capacity of the siege balloons, namely some 70,000 cubic feet, fitted with two screws of about 12 feet diameter, but capable of being readily worked at moderate speed. It was not a success. M. Richard, with three sailors, made a tentative ascent, and used their best endeavours to control their vessel, but practically without avail, and the machine presently coming to earth clumsily, a portion of the gear caught in the ground and the travellers were thrown over and roughly dragged for a long distance.
Fairly looked at, the aerial post of the siege of Paris must be regarded as an ambitious and, on the whole, successful enterprise. Some two million and a half of letters, amounting in weight to some ten tons, were conveyed through the four months, in addition to which at least an equal weight of other freight was taken up, exclusive of actual passengers, of whom no fewer than two hundred were transported from the beleaguered city. Of these only one returned, seven or eight were drowned, twice this number were taken prisoners, and as many again more or less injured in descents. From a purely financial point of view the undertaking was no failure, as the cost, great as it necessarily became, was, it is said, fairly covered by the postage, which it was possible and by no means unreasonable to levy. The recognised tariff seems to have been 20 centimes for 4 grammes, or at the rate of not greatly more than a shilling per English ounce. Surely hardly on a par with famein prices in a time of siege.
It has already been stated that the defenders of Paris did not derive substantial assistance from the services of such a reconnoitring balloon as is generally used in warfare at every available opportunity. It is possible that the peculiar circumstances of the investment of the town rendered such reconnaissance of comparatively small value. But, at any rate, it seems clear that due opportunity was not given to this strategic method. M. Giffard, who at the commencement of the siege was in Paris, and whose experience with a captive balloon was second to none, made early overtures to the Government, offering to build for L40,000 a suitable balloon, capable of raising forty persons to a heightm of 3,000 feet. Forty aerial scouts, it may be said, are hardly needed for purposes of outlook at one time; but it appears that this was not the consideration which stood in the way of M. Giffard's offer being accepted. According to M. de Fonvielle, the Government refused the experienced aeronaut's proposal on the ground that he required a place in the Champs Elysees, "which it would be necessary to clear of a few shrubs"!