Mr. Henry Helm Clayton of the Blue Hill Meteorological Observatory gave a very interesting lecture in the Living Room of the Union last night, on "Navigating the Air." The lecture was illustrated by a large number of lantern-slides showing the growth of the balloon and illustrating the topics on which the lecturer spoke.

We have already conquered the land and the sea, said Mr. Clayton, and we are now beginning the conquest of the air. It was only after the lifting power of the atmosphere and the heating power of gas were discovered that man first rose in the air. Only two years after the discovery of the balloon, Dr. Jeffries of Boston made an ascent for a scientific study of the atmosphere, and soon after crossed the English Channel in his balloon. As was found out after these experiments, the upper strata of the air at a distance of more than five or six miles from the earth, were both too cold and too rarefled for human beings. Mechanical contrivances for recording temperature and pressure were therefore devised and sent up in empty balloons. These were made of rubber which steadily expanded as it rose and finally exploded, forming a parachute that brought the instruments safely back to earth. These experiments were also carried on from yachts.

Besides being a power in science, the balloon can also be used for recreation and pleasure. In Paris, large parties go up for the day. Once in the air, the balloonists drift over valleys and mountains and even rise above the clouds for short periods of time. The sensation of landing, if the airship is skillfully managed, is scarcely perceptible. As the balloon touches the ground, sand-bags are thrown out to lessen the shock. Frequently the balloon is carried along by a sudden wind, dragging basket and occupants over fences and through trees. To prevent such accidents; the ripping cord is used, which tears open the bag and lets the air escape. Often a careless or unlucky balloonist comes down into a forest and has to appeal to some farmer for help in rescuing his balloon. Mr. Clayton narrated some of his ex experiences in travelling from Springfield to Boston by night.

Besides being used for pleasure, balloons can be employed for exploration. Several people have crossed the Sahara desert and have attempted to reach the North Pole in this manner, though without success. In the future, balloons will be used for reconnoitering in times of war, and for this purpose the French have built the "Republique" and the Germans are helping Count Zeppelin construct another dirigible balloon. The great advance that has been made in this line is in the fact that these balloons are driven by motor power.

Gliding machines were first invented by Lilienthal in Germany, and later by Chanute in this country. On their principle the Wright brothers first built their aeroplane. Several years ago they attached a motor to it and, after patenting it in Washington, proceeded to experiment with it. Competing against Frenchmen and Germans they have won the championship of the air and have shown that flying is both possible and practical.