JF Ptak Science Books Quick Post
The story of the (very) long-range bombardment of Paris from points unknown is filled with questions in this article that appeared in the Scientific American on April 6, 1918. The writer hadn't an idea of the type of gun being used, the weight of the shell (yet), and just about all other details. The author did wonder about the reasons for such a gun--that the idea of a long-range indescrimient bombing from a great distance just seemed to be beyond the wanting capacity of the countries fighting Germany.
The big gun was The Big Gun, later identified as the Paris Gun--a mysterious entity during the war, and after the war as well. It turns out that when the Germany army retreated beginning in August that they also destroyed the weapon and just about anything connected to it.
The gun was extremely powerful. At 256 tons it launched a 236-pound shell to a height never before achieved by humans launching/propelling stuff into the air--it left the barrel of the gun at about 1 mile/second, traveled 75 overland miles, reached a height of 26 miles...and then came down, exploding, killing.
One very effective way of explaining the incredible height that the shell reached was measuring the zenith of its trajectory in terms of mountains:
Which is a detail from:
And to give a more local understanding of the range of the gun: