The second what was dropped an hour later and gave the height as 600 metres (2,000 ft)?
Returning to Danes Island in the summer of 1897, the expedition found that the balloon hangar built the year before had weathered the winter storms well. The winds were more favorable, too. Andrée had strengthened his leadership by replacing the older and critical Ekholm, an authority in his field, with the 27-year-old enthusiast Knut Frænkel.On 11 July, in a steady wind from the south-west, the top of the plank hangar was dismantled, the three explorers climbed into the already heavy basket, and Andrée dictated one last-minute telegram to King Oscar and another to the paper Aftonbladet, holder of press rights to the expedition. The large support team cut away the last ropes holding the balloon and it rose slowly. Moving out low over the water, it was pulled so far down by the friction of the several-hundred-meter-long drag ropes against the ground as to dip the basket into the water. The friction also twisted the ropes around, detaching them from their screw holds. These holds were a new safety feature that Andrée had reluctantly been persuaded to add, whereby ropes that got caught on the ground could be more easily dropped.
Most of them unscrewed at once and 530 kilograms (1,170 lb) of rope were lost, while the three explorers could simultaneously be seen to dump 210 kilograms (460 lb) of sand overboard to get the basket clear of the water. Seven hundred and forty kilograms (1,630 lb) of essential weight was thus lost in the first few minutes. Before it was well clear of the launch site, the Eagle had turned from a supposedly steerable craft into an ordinary hydrogen balloon with a few ropes hanging from it, at the mercy of the wind; its crew had no means to direct it to any particular goal and had too little ballast for stability. Lightened, the balloon rose to 700 metres (2,300 ft), an unimagined height, where the lower air pressure made the hydrogen escape all the faster through the eight million little holes.
The balloon had two means of communication with the outside world, buoys and homing pigeons. The buoys, steel cylinders encased in cork, were intended to be dropped from the balloon into the water or onto the ice, to be carried to civilization by the currents. Only two buoy messages have ever been found. One was dispatched by Andrée on 11 July, a few hours after takeoff, and reads "Our journey goes well so far. We sail at an altitude of about 250 m (820 ft), at first N 10° east, but later N 45° east [...] Weather delightful. Spirits high." The second was dropped an hour later and gave the height as 600 metres (2,000 ft).
buoy messages