214 SCIENCE 1$ SHOE! CHAPI-EKS. 



loon. The car was violently shaken. A second and a third explosion 

 followed in quick succession. The danger seemed immediate, when 

 suddenly the balloon recovered her usual form and stillness. These 

 alarming symptoms seemed to have been produced by collapsing of 

 the balloon under the diminished temperature of the upper regions 

 after sunset, and the silk forming into folds under the netting. Now, 

 when the guide rope informed the voyagers that the balloon was too 

 near the earth, ballast was thrown out, and the balloon rising rapidly 

 into a thinner air experienced a diminution of pressure, and conse- 

 quent expansion of the gas. 



" The cold during the night ranged from a few degrees below to 

 the freezing point. As morning advanced the rushing of waters was 

 heard, and so little were the aeronauts aware of the course which 

 .they had been pursuing during the night, that they supposed them- 

 selves to have been thrown back upon the shores of the German 

 Ocean, or about to enter the Baltic, whereas they were actually over 

 the Rhine, not far from Coblentz." 



All this blind drifting for hours, during which the balloon may be 

 carried out to sea, and opportunities cf safe descent may be lost, is 

 averted in an Arctic balloon voyage, which would be made in the 

 summer, when the sun never sets. There need be no break in the 

 survey of the ground passed over, no difficulty in pricking upon a 

 chart the course taken and the present position at any moment. 

 With an horizon of 50 to 100 miles' radius the approach of such a 

 danger as drifting to the open ocean would be perceived in ample 

 time for descent, and, as a glance at the map will show, this danger 

 cannot occur until reaching the latitudes of inhabited regions. 



The Arctic aeronauts will have another great advantage over those 

 who ascend from any part of England. They can freely avail them- 

 selves of Mr. Green's simple but most important practical invention 

 the drag rope. This is a long and rather heavy rope trailing on 

 the ground. It performs two important functions. First, it checks 

 the progress of the balloon, causing it to move less rapidly than the 

 air in which it is immersed. The aeronaut thus gets a slight breeze 

 equivalent to the difference between the velocity of the wind and 

 that of the balloon's progress. He may use this as a fulcrum to 

 effect a modicum of steerage. 



The second and still more important use of the drag rope is the 

 very great economy of ballast it achieves. Suppose the rope to be 

 1000 feet long, its weight equal to 1 Ib. for every ten feet, and the 

 balloon to have an ascending power of 50 Ibs. It is evident that un- 

 der these conditions the balloon will retain a constant elevation of 

 500 feet above the ground below it, and that 500 feet of rope will trail 

 upon the ground. Thus, if a mountain is reached no ballast need be 

 thrown away in order to clear the summit, as the balloon will always 

 lift its 500 feet of rope, and thus always rise with the up-slope and 

 descend with the down-slope of hill and dale. The full use of this 

 simple and valuable adjunct to aerial travelling is prevented in such 

 a country as ours by the damage it might do below, and the tempta- 

 tion it affords to mischievous idiots near whom it may pass. 



In the course of many conversations with various people on this 

 subject I have been surprised at the number of educated men and 

 women who have anticipated with something like a shudder the terri- 

 ble cold to which the poor aeronauts will be exposed. 



