From page 76, The New York Public Library Science Desk Reference (copyright 1995):  "Right now, the
moon, at a mean distance of 238,866 miles , moves away from the earth a few centimeters per year.  
Some scientists believe that the moon's rotation and revolution will eventually be 47 days and at a
distance of 347,984 miles from earth."

From UB paper 57 (copyright 1955).
When the tidal frictions of the moon and the earth become equalized, the earth will always turn the
same hemisphere toward the moon, and the day and month will be analogous—in length about forty-
seven days. When such stability of orbits is attained, tidal frictions will go into reverse action, no longer
driving the moon farther away from the earth but gradually drawing the satellite toward the planet.

By Paul Herrick