Webster's Tenth Collegiate Dictionary gives the first usage of the term
"floating point" as 1948.
R. K. Richards _Arithmetic Operations in Digital Computers _ (Princeton, New
Jersey: D. Van Nostrand Company, Inc., 1955) includes a discussion (page 317)
of a series of computers built by Bell Laboratories bewteen 1940 and 1950.
These were electromechanical computers with relays doing most of the work.
"The floating-decimal-point idea seems to have appeared first in the Bell
Laboratories Mode V, which was completed in 1946".
James A Landau