The Dominion of the Air [79]
at the Orleans station the material was coloured and entrusted only to hand stitching. The allimportant detail of varnish was supplied by a mixture of linseed oil and the active principle of ordinary driers, and this, laid on with a rubber, rendered the material gas-tight and quickly dry enough for use. Hundreds of hands, men and women, were employed at the two factories, at which some sixty balloons were produced before the end of the siege. Much of the more important work was entrusted to sailors, who showed special aptness, not only in fitting out and rigging the balloons, but also in their management when entrusted to the winds.
It must have been an impressive sight for friend or foe to witness the departure of each aerial vessel on its venturesome mission. The bold plunge into space above the roofs of the imprisoned city; the rapid climb into the sky and, later, the pearl drop high in air floating away to its uncertain and hazardous haven, running the gauntlet of the enemy's fire by day or braving what at first appeared to be equal danger, attending the darkness of night. It will be seen, however, that, of the two evils, that of the darkness was considered the less, even though, with strange and unreasonable excess of caution, the aeronauts would not suffer the use of the perfectly safe and almost indispensable Davy lamp.
Before any free ascents were ventured on, two old balloons were put to some practical trial as stationary observatories. One of these was moored at Montmartre, the other at Mont-souris. From these centres daily, when the weather permitted, captive ascents were made--four by day and two by night--to watch and locate the movements of the enemy. The system, as far as it went, was well planned. It was safe, and, to favour expedition, messages were written in the car of the balloon and slid down the cable to the attendants below. The net result, however, from a strategic point of view, does not appear to have been of great value.
Ere yet the balloons were ready, certain bold and eventful escapes were ventured on. M. Duruof, already introduced in these pages, trusting himself to the old craft, "Le Neptune," in unskyworthy condition, made a fast plunge into space, and, catching the upper winds, was borne away for as long a period as could be maintained at the cost of a prodigal expenditure of ballast. The balloon is said to have described a visible parabola, like the trajectory of a projectile, and fell at Evreux in safety and beyond the range of the enemy's fire, though not far from their lines. This was on the 23rd of September. Two days afterwards the first practical trial was made with homing pigeons, with the idea of using them in connection with balloons for the establishment of an officially sanctioned post. MM. Maugin and Grandchamp conducted this voyage in the "Ville de Florence," and descended near Vernouillet, not far beyond Le Foret de St. Germain, and less than twenty miles from Paris. The serviceability of the pigeon, however, was clearly established, and a note contributed by Mr. Glaisher, relating to the breeding and choice of these birds, may be considered of interest. Mr. R. W. Aldridge, of Charlton, as quoted by Mr. Glaisher, stated that his experience went to show that these birds can be produced with different powers of orientation to meet the requirements of particular cases. "The bird required to make journeys under fifty miles would materially differ in its pedigree from one capable of flying 100 or 600 miles. Attention, in particular, must be given to the colour of the eye; if wanted for broad daylight the bird known as the 'Pearl Eye,' from its colour, should be selected; but if for foggy weather or for twilight flying the black- or blue-eyed bird should receive the preference."
Only a small minority, amounting to about sixty out of 360 birds taken up, returned to Paris, but these are calculated to have conveyed among them some 100,000 messages. To reduce these pigeon messages to the smallest possible compass a method of reduction by photography was
It must have been an impressive sight for friend or foe to witness the departure of each aerial vessel on its venturesome mission. The bold plunge into space above the roofs of the imprisoned city; the rapid climb into the sky and, later, the pearl drop high in air floating away to its uncertain and hazardous haven, running the gauntlet of the enemy's fire by day or braving what at first appeared to be equal danger, attending the darkness of night. It will be seen, however, that, of the two evils, that of the darkness was considered the less, even though, with strange and unreasonable excess of caution, the aeronauts would not suffer the use of the perfectly safe and almost indispensable Davy lamp.
Before any free ascents were ventured on, two old balloons were put to some practical trial as stationary observatories. One of these was moored at Montmartre, the other at Mont-souris. From these centres daily, when the weather permitted, captive ascents were made--four by day and two by night--to watch and locate the movements of the enemy. The system, as far as it went, was well planned. It was safe, and, to favour expedition, messages were written in the car of the balloon and slid down the cable to the attendants below. The net result, however, from a strategic point of view, does not appear to have been of great value.
Ere yet the balloons were ready, certain bold and eventful escapes were ventured on. M. Duruof, already introduced in these pages, trusting himself to the old craft, "Le Neptune," in unskyworthy condition, made a fast plunge into space, and, catching the upper winds, was borne away for as long a period as could be maintained at the cost of a prodigal expenditure of ballast. The balloon is said to have described a visible parabola, like the trajectory of a projectile, and fell at Evreux in safety and beyond the range of the enemy's fire, though not far from their lines. This was on the 23rd of September. Two days afterwards the first practical trial was made with homing pigeons, with the idea of using them in connection with balloons for the establishment of an officially sanctioned post. MM. Maugin and Grandchamp conducted this voyage in the "Ville de Florence," and descended near Vernouillet, not far beyond Le Foret de St. Germain, and less than twenty miles from Paris. The serviceability of the pigeon, however, was clearly established, and a note contributed by Mr. Glaisher, relating to the breeding and choice of these birds, may be considered of interest. Mr. R. W. Aldridge, of Charlton, as quoted by Mr. Glaisher, stated that his experience went to show that these birds can be produced with different powers of orientation to meet the requirements of particular cases. "The bird required to make journeys under fifty miles would materially differ in its pedigree from one capable of flying 100 or 600 miles. Attention, in particular, must be given to the colour of the eye; if wanted for broad daylight the bird known as the 'Pearl Eye,' from its colour, should be selected; but if for foggy weather or for twilight flying the black- or blue-eyed bird should receive the preference."
Only a small minority, amounting to about sixty out of 360 birds taken up, returned to Paris, but these are calculated to have conveyed among them some 100,000 messages. To reduce these pigeon messages to the smallest possible compass a method of reduction by photography was