Lots of their ideas involve mechanized devices, flying, or a combination of the two. Some, strangely, involve people interacting in a very close and personal way with marine life. As Open Culture points out, however, there are no images of space travel.
Some of the portraits are fantastic -- swashbucklers riding on giant seahorses, anyone? But others are actually surprisingly accurate visions of our current era, including farming machines, helicopters, and what looks like a precursor to the new robot vaccum, the iRobot Roomba vacuum:
There is something vaguely familiar about these visions of mechanized farming, for example:
Perhaps this is the precursor to the motorhome?
However, some of the other machines didn't quite come to pass:
The series also features a great assortment of flying machines and devices, including a helicopter:
One drawing features an airship, which were being used at the time, but fell out of favor after the Hindenburg disaster in 1937:
The series imagines small winged planes or devices being used by cabbies, postmen, police, firemen and hunters:
Here's their conception of a "war plane" and "war cars":
Strangely, the series also includes some fairly far-out examples of people cavorting with marine life:
And finally, the "Whale bus," which really ought to be a thing by now: