Bessell function

How did Bessell first use his function? I seem to recall it related to
astronomy, but no mention in the big Watson book.
ray@xxxxxxxxxxxx
www.iinet.com.au/~ray
http://en.wikipedia.org/wiki/On_Liberty
"The preventive function of government, however, is far more liable to be abused, to the prejudice of liberty, than the punitory function; for there is hardly any part of the legitimate freedom of action of a human being which would not admit of being represented, and fairly too, as increasing the facilities for some form or other of delinquency."
J S Mill
.

Relevant Pages