The Peregrine, CHAPTER VIII.
Withdrawing from comparisons between multiple future history series, we appreciate specific details in a single future history instalment although here again we can find some comparisons. When the Nomad spaceship, the Peregrine, departs from a planetary system, the ship cannot enter hyperspace until the gravitational field is sufficiently weak. That is fairly standard and certainly applies to the different kind of hyperspace in Poul Anderson's later Technic History. In the Peregrine, human bodies experience:
"The indescribable twisting sensation of hyperdrive fields building up..." (p. 57)
I have read that or something like it elsewhere although maybe not in the Technic History?
In the Peregrine, a telepath senses cerebral emissions but cannot interpret characteristic individual patterns and this corresponds exactly to how telepathy operates in the Technic History - excepting only Aycharaych, the universal telepath. Characters in different series cannot know how close they are to each other. Sundered by their alternative histories, they are nevertheless united in their creator's and readers' imaginations.