Haertel Timelines

Although James Blish's Haertel Scholium does not comprise a single linear future history series, it could be republished in a boxed-set uniform edition with minimal editing. Such a set should exclude the novel, A Case Of Conscience, because that is Volume III of the After Such Knowledge Trilogy and need not be collected twice, which leaves six volumes:

Two Adolph Haertel Volumes

Welcome To Mars

Galactic Cluster: Revised Edition ("No Jokes on Mars" + the short Haertel trilogy)

These first two volumes cover:

Haertel on Mars

Mars

Haertel

Haertel's successors

Two Jack Loftus Novels

The Star Dwellers

Mission To The Heart Stars (+ "A Dusk of Idols")

Two Thor Wald Volumes

The Quincunx Of Time (+ "A Style in Treason")

Midsummer Century

The second and third pairs cover alternative successors of Haertel.

There are alternative versions of Mars and also of the galactic centre. The Haertel who is directly referenced in Mission To The Heart Stars and the Haertel who is indirectly referenced in "This Earth of Hours" cannot be the same Haertel because these works present mutually incompatible accounts of what is to be found at the galactic centre. Consequently, Haertel exists in different timelines.

Versions Of Mars

In James Blish's Cities In Flight, Volume I, They Shall Have Stars, and in the second of Blish's two Jack Loftus novels, Mission To The Heart Stars, the long extinct Martians had covered their planetary surface with the Diagram of Power.

In Blish's first Haertel Scholium novel, Welcome To Mars, Martian canals are crustal faults or spalled cracks caused by meteor impacts and the intelligent six-foot-long dune-cats had been domesticated by the just-extinct Old Martians whereas, in "No Jokes on Mars," the four-foot-long but otherwise identical dune cats (unhyphenated) are possibly descended from the long-extinct Canal Masons.

In After Such Knowledge, Volume III, A Case Of Conscience, there are unintelligent Martian sand crabs.

The "Diagram of Power" Mars exists in two timelines, those of Cities In Flight and of the Loftus novels.

Although Blish stated that "No Jokes on Mars" was set at least a decade later than Welcome To Mars, it is clear that the story and the novel are set on similar but different versions of Mars and therefore in different timelines.

Neither version of the dune-cats exists on the "Diagram of Power" Mars but the sand crabs might although there is no reason to think that they do.