Comprises correspondence between David V. Thomas and fhe following correspondents:
Bazlur Rahman at Survey of Pakistan;
Harold W. P. Richards at Royal Greenwich Observatory;
John A. Decker Jr. at Comstock & Westcott, Inc, Cambridge, Massachusetts;
The Director, Trigonometrical Survey, Mowbray, South Africa;
S. K. Sharma at Survey of India;
H. Enslin at Deutsches Hydrographisches Institut, Hamburg, Germany;
D. H. Sadler at H. M. Nautical Almanac Office, Royal Greenwich Observatory;
The Director, Observatoire d'Alger, Bouzerea, Algeria;
Y. Väisälä, Turku, Finland;
R. E. Wallis at Royal Observatory, Cape of Good Hope, South Africa;
W. Gliese at Astronomisches Rechen-Institut, Germany;
Francis P. Scott and B. L. Klock at US Naval Observatory;
Carlos A. Kurtz, Buenos Aires, Argentina;
S. Débarbat at Observatoire de Paris;
Walter Fricke at Astronomisches Rechen-Institut, Germany;
Luiz Muniz Barreto at Observatório Nacional, Rio de Janeiro, Brazil.