March 9, 1871 | 
NATURE 
371 

reigning ¢tirrent was astrong S. W. wind, which was unfavourable 
for escaping the Prussian lines, as the intended directing power 
was only a motion of three feet per second. The experiment 
should have been postponed for a fair trial. Another drawback 
to the Expedition was the despatch of the balloon in the night- 
time, although the moon, being almost full at the time, afforded 
some light to the aérial travellers, being very low on the 
horizon when ‘Le Duquesne” left the Orleans railway station. 
There were in the car M. Richard and three sailors of the national 
navy, so that two could be kept pulling without interruption ; 
three sacks of despatches, four pigeons, eight sacks of ballast, 
thirty kilogrammes each, were also inthe car. The provisions 
were bread, wine, and chocolate. The weight of the machinery 
was 300 pounds. As will be seen by the accompanying diagram, 
the two screws were worked by a very simple contrivance, 
rotating only at a rate of twenty-five rotations per minute, but 
the diameter four yards, so that the motion in feet per second 
of the screws was about sixteen, five or six times more than the 
rapidity intended to be given to the balloon, which was three 
miles an hour. 
Before leaving ground the car had been placed with its diagonal 
due north, But that precaution proved useless, as the balloon 
rotated when ascending before the screws could be put into 
operation. 
We will give the explanation under M. Richard’s own authority, 
with some remarks. We are certain of his perfect truthfulness, 
but it is very hard to say if he saw everything correctly for the 
whole length of the eventful journey. 
B&UEVATION 

THE DUQUESNE DIRECTING BALLOON, DESPATCHED FROM PARIS 
JANUARY 9, 1871 
a@aaasegments of the screw revolving in the direction of the arrow or 
the opposite direction, with variable rapidity; 4 valve line; c car; @ 
aopendage @ hoop, : 
AAhandle for moving screw, two men pulling at once ; c place of the 
captain; B place of one man ; D D board in iron tubes fixed to the car; EE 
extremities of the axes; F F fixing screw, which can be removed s) that 
wheels may be thrown overboatd when landing: 
The observers on the ground had placed themselves in a right 
position to ascertain the effect of the screws, and the covt/te- 
vendu published in Paris gave the summary of their impressions. 
They suppose M. Richard succeeded in giving to his balloon a 
deviation of 15° from the due course of the wind during the earlier 
part of his journey. If experiments had been made during 
daylight, matters should have been more easy toascertain. If I 
can procure authorisation, I will get an experiment tried anew at 
the Crystal Palace before an English audience. The fact is that 
two of the three sailors pulled with all their strength during a few 
minutes, after having exhibited some hesitation inthe first instance, 
The scenery was so magnificent that it was necessary to call them 
twice before they began to pull. ’ 
M. Richard soon perceived that he was unable to ascertain 
the effect of the propeller. He resolved upon letting th: balloon 




follow its way undisturbed, and he noted carefully the barometric 
altitude and the direction. When passing over Prussian lines at an 
altitude of o“™-69, some shots were directed at the balloon without 
any result. 
At 3" ro™ altitude 0°68° was reached; temperature 20° F. 
The Valley of the Marne was below. 
M. Richard turned the screws and tried to pull towards the north, 
in order to go N.N.E; but the rotation was difficult to stop. It 
was necessary to work only one screw during a long time in order 
to rotate the aérostat in the right direction. It was only when 
some real torsion was established between aérostat ‘and car that 
the required revolution took place. But when movement was 
given to the balloon it was difficult to prevent it, and the aérostat 
executed one entire revolution against the will of its captain. 
Then the two screws were worked together ; the same effects were 
produced, but it was only with great difficulty that the car was 
placed in the right direction, When the two screws were worked 
together, the balloon: was rotating sometimes in one way and 
sometimes in another. These observations, moreover, says M. 
Richard, were made at night bya man who had never before 
ascended in a'balloon. As already said they cannot be considered 
as wholly reliable, as rotation depends on the changingof the fuel 
as well as on the friction in the forward half or on inequality in the 
pulling of the screws. But it is very easy to understand that 
the fact of the screws being able to rotate the balloon in a given 
direction is unquestionable, although men and captain were equally 
unable to move it in the right direction for escaping Prussian 
lines. 
The difficulties experienced were so great that M. Richard 
stopped the experiment, and tried it ugain only after day-break, 
but with no other success than previously. 
At 7 o’clock in the morning, altitude 65 centimetres, temperature 
Ir Fahr., cirrus was visible at a great height, cumulus down 
below, and stratus covering the earth. 
At 11 o'clock only one sack of ballast was left. The balloon 
stopped its descent ; voices of peasantry were heard from above the 
stratus. They cry ‘‘Versy; commune of Chigny.” The balloon 
emerging in stratus, fell rapidly by condensation. All the ballast 
was thrown away, and the balloon ran horizontally for two miles. 
The guide rope only had been thrown ; thenthe grapnel was thrown 
out. The wind was so strong that the grapnel rope was broken. 
The serews and wheels had been thrown overboard, but the car 
incliners and the screw axes project outside. One of these comes 
into contact with the ground, the car is upset, and the crew are 
dragged under it for a length of time, 600 yards. The balloon is 
stopped by the loss of gas and the peasantry. The three sailors 
are slightly injured, the captain is left for dead. The sailors, 
helped by the peasantry, make their escape, and conceal 
balloon, car, and despatches in the woods. The captain is brought 
like a corpse into a neighbouring town, but is found to be alive. 
He is cured, and sent secretly into Lille, where the balloon 
arrived two days later. 
W. DE FONVIELLE 



NOTES 
AT arecent meeting of the American Philosophical Society 
it was resolved ‘That a committee, consisting of the President 
of the Society and five members, be appointed, whose duties it 
shall be to consider and report whether it is desirable, and if 
desirable, whether it be practicable, to establish in the City of 
Philadelphia, under the auspices of the Society, an Observatory, 
astronomical and physical, either or both ; and if so at what cost, 
on what site, and what instruments are requisite for such pur- 
poses, and at what cost such instruments can be procured.” We 
suppose such a proposal for England would be looked upon as a 
joke, and yet already we cannot compare with America in our 
observing power. 
WE are informed that the Royal Commission on Scientific 
Instruction and the Advancement of Science have their First 
Report nearly ready. 
Dr. J. CLERK MAXWELL, F.R.S., was elected yesterday to 
the Professorship of Experimental Physics in the University of 
Cambridge, 
