owards the close of the war between France and Germany, in 1870, the German troops lay so closely round the walls and fortifications of Paris that all communication with the outside world was cut off. No letters could be sent to friends, and no letters from friends could be received, for, once outside the walls of the town, they would surely fall into the hands of the enemy. But the post office was anxious to continue doing its duty, and the Government felt bound to find some means for sending out and receiving official dispatches. The only way to accomplish this was by the use of balloons. Paris had always been very busy with balloons, but, when inquiries were made, it was found that there were not more than six in all the city, and these were far too old and worn out to use. Balloons must, therefore, be made, said the authorities, and two gentlemen, named Godard and Yon, were requested to begin the work at once. As railway stations were not wanted for trains in Paris at that particular time, the two largest were chosen in which to build balloons. Henceforth their 'trains' would journey silently through the sky instead of noisily over the iron roads.

Needles and cotton and calico were all carried in large quantities to the Gare du Nord and the Gare d'OrlÉans (as the two stations are called), and in less than four months sixty balloons were built and dispatched.

Some people in Paris, however, were so anxious to try the experiment that they could not wait for the new balloons, but used an old one, called the 'Neptune,' and M. Durnof, a daring aeronaut, made a flying dash in it out of Paris. Those who witnessed his adventure say that the old Neptune bounded almost straight up into the air, and fell beyond the enemy's camp in much the same manner. It was as though a large cannon ball had been fired (only very slowly) from the streets of Paris.

The successful path of the Neptune was soon followed. M. Gambetta, the great statesman, stepped into the car of the 'Armand BarbÈs' on the morning of October 7th, and, after many narrow escapes from the enemy's guns, landed safely among friends. Three days later a pretty grey-feathered pigeon settled in Paris, bringing in one of its quills the story of his journey.

But among the many wonderful ascents made in that terrible time, none is more interesting than that of M. Janssen, a great astronomer, who went to Algeria to see an eclipse of the sun. Certain learned societies in France, very anxious that the progress of science should not be delayed by this unhappy war, were delighted to find him willing to undertake the dangerous journey. England offered to obtain a safe-conduct for him through the Prussian camp, but the astronomer said: 'No, thank you. I do not wish to be under any obligation to the enemy.'

So, packing his telescope and other instruments with very great care, he carried them to the Gare d'OrlÉans on the morning of the 2nd December (three weeks before the eclipse would take place), and, settling himself in the car of his white balloon, the 'Volta,' gave orders for the anchor to be weighed. At that time in the morning it was quite dark, and, ere daylight was an hour old, he and his companion (a young sailor) had come to earth again by the mouth of the Loire. They had travelled nearly three hundred miles in a little more than three hours. A swifter journey has hardly ever been made. It is disappointing to learn that, after such a daring exploit, M. Janssen reached his destination only to find dense clouds covering the Algerian sky at the moment the eclipse took place.

The frequency with which balloons left Paris soon made it necessary to increase the number of aeronauts, for those who departed were, of course, unable to return. As the professional men became fewer, it was found that the best to take their places were sailors. But, that they might first have lessons in the art, a car was suspended from the roof of the factory, and into this the sailor-pupil climbed. He soon learned how to cry out, 'Let go all!' Then, after throwing out the ballast, pulling the valve-rope, and dropping the anchor, he was ready, with more courage than discretion, to call himself an aeronaut. And into the air he went, with bags of letters and cages of pigeons, and, on the whole, succeeded very well as a postman in the clouds.

The mention of pigeons leads us to another story of ingenuity, though it has not much to do with balloons.

After the question of how to dispatch letters had been solved, the next that arose was, how to receive replies. The balloons that left the city had got nearly all Europe to settle in, but it was hopeless to try to steer them back to so small a spot as the city itself. But a carrier pigeon would have no such difficulty in returning. Means must be found, however, to make it possible for each bird to carry many letters. M. Dagron, a clever photographer, discovered this means. He showed how he could photograph a letter and reduce it in size till the writing became unreadable, even under an ordinary magnifying glass. This could be done on films so thin that a roll of twenty of them could be inserted in one quill, each film representing a large number of letters. Having proved to the authorities the success of his invention, M. Dagron departed in a balloon, to explain to the various towns in France how letters must be sent to Paris.

Every day after that the welcome sounds of flapping wings was heard in the beleaguered city. The letters that they brought were placed between two sheets of glass and enlarged. Then, by means of a magic lantern, they were reflected on to a large screen, while post-office clerks, sitting at a table opposite, copied them down on to separate sheets, and dispatched them to their different addresses in the city. Nearly one hundred thousand letters were sent to Paris in this way during the four months of the siege, and the hostile army outside its walls was powerless to intercept them.

John Lea.