<<From Earth to Moon>>

I have read that the gun Verne describes is essentially a technology that has since been developed, and is called a "rail gun." It involves a pair of charged parallel rods the projectile is hurled by plasma. This overcomes the barrier of maximum velocity to which gas expanding in a tube can excellerate, something like 20,000 mph. This, however, is another 'fact' retrieved from boyhood memory.

As to your original question, what is "futurism." (sorry, no time to look)