Scarce material (1)

Tang Zhen's drawing had many weapons and equipment on it. The most powerful weapon was naturally the cannon.

This kind of weapon was once used on a large scale in the war in his original world and also existed in other planes. It was naturally Tang Zhen's first choice.

Although it looked ordinary, its power was considerable. It was definitely the most suitable weapon to defend the Heaven's Wall city.

With the church of the alarm Bell's ability, it was entirely possible to produce cannons, but due to the limitations of the materials, it was likely that it could not be mass-produced.

This was because every cannon required a large amount of metal. However, in this world with low productivity, metal was often the most precious strategic material.

Even if the Heaven's Wall city had a special situation and had accumulated a large number of metal ores from years of mining, it still could not support this consumption.