The description of giant versions of technologies already in use is very frequent in WWI technoscientifical popularization. If the existing weapons were so lethal surely augmenting their size would have augmented their efficacy (and their spectacularity in the eyes of the readers).
The Big Gun, for example, was meant to be 114 metres long and to be able to shoot 100 tons shells at a 160 km distance. The biggest gun actually used during the conflict, the Paris-Geschutz, shot 100 kg shells within a 130 km range. A shell shot by the imaginary super-cannon, loaded with toxic gas and landing on a German city, would have made the place a "valley of death" for thirty days.
This apocaliptic vision, realized and exceeded by the atomic bomb 30 years later, was criticized by the magazine editors (how to build it? How to move it? Would it really have been more efficent than the existing guns?). But the doubts do not prevent the magazine from publishing the invention, accompanied by illustrations that put the enourmous gun in comparison with every-day innocuous objects (a common practice in science popularization, meant to catch the attention of the readers and to attenuate the weapons' violence).
Electrical Experimenter publishes an electromagnetic gun, patented by various inventors since 1915. A series of electro-magnetic fields would have pushed the shells out of the barrell with no explosions, smoke or deterioration of the barrell itself (a pressing problem in real WWI artillery). The cannon was supposed to work as a giant machine gun, shooting 50-70 projectiles a minute at a distance of fourty km. The idea of an electromagnetic gun will be devoloped after the war and have lead, in recent years, to many prototypes (railguns), but no widespread use in battle.
Popular Science Sifting imagination focuses on the munitions, proposing a Shower Shell. Like a shrapnel it was supposed to release its load just above the enemies heads. But instead of lead balls the shower shell was meant to release smaller high-velocity explosive shells. Popular Science Monthly suggests instead a mortar shell that releases barbed wire in front of the enemy.