  We propose a simple procedure for evaluating the main thermodynamical
attributes of a Schwarzschild's black hole: Bekenstein-Hawking entropy,
Hawking's temperature and Bekenstein's quantization of the surface area. We
make use of the condition that the circumference of a great circle on the black
hole horizon contains finite number of the corresponding reduced Compton's
wavelength. It is essentially analogous to Bohr's quantization postulate in
Bohr's atomic model interpreted by de Broglie's relation. We present black hole
radiation in the form conceptually analogous to Bohr's postulate on the photon
emission by discrete quantum jump of the electron within the Old quantum
theory. It enables us, in accordance with Heisenberg's uncertainty relation and
Bohr's correspondence principle, to make a rough estimate of the time interval
for black hole evaporation, which turns out very close to time interval
predicted by the standard Hawking's theory. Our calculations confirm
Bekenstein's semiclassical result for the energy quantization, in variance with
Frasca's (2005) calculations. Finally we speculate about the possible
source-energy distribution within the black hole horizon.
