Section 1. Introduction to Problem
On 1 November 1946, the Research Division of the College of Engineering of New York University entered into Contract No. W28-099-ac-241 with Watson Laboratories, Air Materiel Command. Under this contract, the University was commissioned to design, develop and fly constant-level balloons to carry instruments to altitudes from 10 to 20 km, adjustable at 2 km intervals.
The following performance was specified:
a. Altitude shall be maintained within 500 meters
b. Duration of constant-level flight to be initially 6 to 8 hours minimum; eventually 48 hours
c. The accuracy of pressure observations shall be comparable to that obtainable with the standard Army radiosonde ( 3 to 5 mb)
Monthly reports have been submitted to describe the progress of the project, however, much data and details of technical nature were given only in a qualitative way. It is intended to collect these data in this technical report and to review at the same time the total achievement of this phase of the project.
Section 2. Method of Attack
A. Balloons
A survey was made of previous attempts to produce a constant-level balloon; such as, the experiments by Meisinger $ ^{1} $ with manned balloons, the shrouded meteorological balloon developed by Dewey and Almy $ ^{2} $ , the Japanese balloon bombs $ ^{3} $ , and the clusters of meteorological balloons which have been used in cosmic ray investigations by Compton, Korff and others $ ^{4} $ .