Tank Drawing

The tank is the 20th century realization of an ancient concept: that of providing troops with mobile protection and firepower. Since biblical times men had constructed or imagined such vehicles propelled by human or animal muscle-power, by sail, or more recently, by steam power. Only when comparatively recent technologies were combined did the tank became a practical possibility; those were the internal combustion engine, armour plate, and the continuous track.
Armoured trains appeared in the mid-19th century, and various armoured steam- and petrol-engined vehicles were also proposed. The first armoured car was produced in Austria in 1904. However, all were restricted to rails or reasonably passable terrain. It was the development of a practical caterpillar track that provided the necessary independent, all-terrain mobility.
Many sources imply that Leonardo da Vinci and H.G. Wells in some way foresaw or "invented" the Tank. Da Vinci's late 15th century drawings of what some describe as a "tank" show a man-powered, wheeled vehicle with cannons all around it. The machines described in Wells's 1903 short story The Land Ironclads are a step closer, in being armour-plated, having an internal power plant, and being able to cross trenches. Some aspects of the story foresee the tactical use and impact of the tanks that later came into being. However, Wells's vehicles were driven by steam and moved on Pedrail Wheels, technologies that were already outdated at the time of writing. After seeing British tanks in 1916, Wells denied having "invented" them, writing, "Yet let me state at once that I was not their prime originator. I took up an idea, manipulated it slightly, and handed it on." It is, though, possible that one of the British tank pioneers, Ernest Swinton, was subconsciously or otherwise influenced by Wells's tale.
The "caterpillar" track arose from attempts to improve the mobility of wheeled vehicles by spreading their weight, reducing ground pressure, and increasing their adhesive friction. Experiments can be traced back as far as the 17th century, and by the late nineteenth they existed in various recognizable and practical forms in several countries.