As often as we got rid of the low clouds, Mr. Calwagen sent up the pilot balloons for observing the wind’s direction and strength. These observations were of the greatest value for judging the weather conditions, and I will therefore mention them in a few words here. The observations took place as follows: A colored rubber balloon is filled with water gas until it is one-half meter in diameter. One weighs its buoyancy and thereby knows the speed with which it will rise into the air. After the balloon has been sent up it is observed through glasses which have graduated scales for calculating necessary horizontal and vertical adjustments--this is called a theodolite. The theodolite’s indications are read and noted each half minute whilst the balloon rises. Afterwards it is possible to reconstruct the course which the balloon has followed, and to ascertain hereby the course of the wind at the different heights. It was not always easy to find a suitable place to set up the theodolite. On board the “Fram” it very often happened that the balloon after some minutes got behind the ship’s masts or funnel, and thereby was lost from view. On the ice in the fjord it was generally possible to find a good spot with the exception of the days when there was a heavy swell on the water outside, which also set the fjord ice making slight undulating movements, and which were disturbing enough when it was a question of reading one-tenth of a degree on the theodolite. Near Danskeöen, where there was no useful fjord ice, Mr. Calwagen had to be rowed ashore for each pilot observation in order to have firm ground below the theodolite. Generally he chose the little islet “Likholmen,” where he could sit and have an uninterrupted view on all sides. When the “Fram” went out to get fresh water-ice from an iceberg which had got aground, Mr. Calwagen was there immediately and set his apparatus up on the iceberg. This is probably the first time that pilot balloon observations have been made from an iceberg. With the execution of all these pilot balloon observations, under conditions which were continually changing and often difficult,* Mr. Calwagen had to use all his care and all his skill. It can certainly be said that he made use of every possibility imaginable in order to collect data which might be helpful in supplementing the expedition’s weather forecasts.