REFERENCES
- A. G. Greenhill , Determination of the greatest height consistent with stability that a vertical pole or mast can be made, and of the greatest height to which a tree of given proportions can grow , Proc. Camb. Philo. Soc. 4 65 ( 1881 ).
- C. Y. Wang and B. Drachman , Stability of a heavy column with an end load , J. Appl. Mech. 48 668 ( 1981 ).
- COMMUNICATED BY E. J. HAUG