"I kind of take it for granted that our great-grandchildren will regard us as a sort of precursor species. That they won't think of us as human and if we could see them, we probably wouldn't think of them as human either."
- William Gibson

Eando Binder used this phrase in Murder on the Asteroid in 1933:

In the wall nearest the hull was an air seal. He opened this. In the tiny chamber revealed rested a small ellipsoid metal object with a bulge of steel-glass on its top surface — the “life boat.”

Due to the constant dangers of meteors in space which might at any moment crash through an ether boat, each space vehicle carried one or more of the life boats. They were simply little one-man ether boats, miniature models of the larger craft, equipped with small but efficient rocket motors. If for any reason the larger boat became unmanageable, damaged, or useless as a vehicle, the passenger could then embark in the life boat and propel himself within reach of rescue. Each life boat was equipped with a radio. They also carried food, oxygen, and heating apparatus.

Hanson, holding the little man in his arms, smirked as he saw the dull metal ellipsoid boat, for it entered his plans of the moment. On its side was emblazoned the same number as was on the outside hull of the bigger boat — P-322-M-505.

Doc Smith used this phrase just a year later in Triplanetary:

Through the airlock, down through several levels of passenger's quarters they hurried, and into a lifeboat.