Flying Mountains

In Larry Niven's and Jerry Pournelle's The Mote In God's Eye (London, 1959), an asteroid is described as a "...flying mountain." (p. 159) This evokes yet another Poul Anderson future history, although not one of the sequence of seven: Tales Of The Flying Mountains.

In ...Mountains, as in James Blish's Cities In Flight future history, space technology is based on control of gravity although in this case such technology facilitates asteroidal colonization but does not lead to an FTL drive.

I identified six future historical themes:

(i) near future technological advances and social changes;
(ii) a period of interplanetary travel;
(iii) an FTL drive;
(iv) extrasolar colonization;
(v) interstellar imperialism;
(vi) the rise and fall of civilizations -

- while acknowledging that not every future history addresses all of these themes. In fact, ...Mountains can alternatively be summarized as follows:

(i) and (ii) as above;
(iii) an STL drive;
(iv) the first extrasolar colonists still in flight.

...Mountains focuses on (ii) the interplanetary period and thus parallels:

Heinlein's The Green Hills Of Earth;
Asimov's I, Robot;
Blish's They Shall Have Stars;
Niven's Lucas Garner/Gil the Arm stories.

Anderson's other future histories also diverge from the (i)-(vi) model by omitting (iii) FTL and (v) interstellar imperialism.