A BRIEF reference was made in NATURE of February 23, p. 299, to the remarkable preparations afoot in the United States to launch a new attempt in stratosphere research following on the mishap to Explorer I. News has now come to hand that everything was ready by June 1 and the balloonists are only awaiting favourable weather conditions. The outstanding feature of this new experiment is the display of co-ordination of effort on the part of the National Geographic Society, the U.S. Army Air Corps and many of the public bodies interested in research. Capts. A. W. Stevens and O. A. Anderson will again ascend, and Capt. R. P. Williams is in charge of ground operations and has been named as alternative pilot.