An experiment in aerial navigation crowned with complete success has just been accomplished at the militaryworkshop at Chalais. The object of the accompanyingreport is to make known to the Academie the results obtained.

On the 9th August, at four o'clock in the afternoon, anascent was made there, in a fish–shaped balloon. It wasfitted with a screw and a rudder, and was manned by CaptainRenard (Engineers) the director of the workshops, andCaptain Krebs (Infantry) who has worked with him for sixyears. After a total distance of 4–71 miles had been coveredin twenty–three minutes, the balloon made its descent at thesame point from which it had started. During the journeyit executed a series of manoeuvres with a precision comparableto that of a steamer moving upon water.

The solution of this problem has been already attempted in 1855, by M. Henri Giffard, who used steam power. In 1872, by M. Dupuy de Lome, who used the muscular force of men, and lastly, by M. Tissandier in 1883, who last year was the first to apply electricity to the propulsion of balloons. But its solution has remained until this day very imperfect, for in no case has the aerostat been able to return to the point of its departure. We have been guided in our labours by the calculations made by M. Dupuy de Lome for the construction of his aerostat of 1870–72, and have besides devoted ourselves to the fulfilment of the following condition.