|Weights and loads|
Besides his countless other activities the great Russian scientist Mikhail Vasil'evich Lomonosov also tried to construct in model size a flying machine "heavier-than-air" which he called "aerodromic". With this he hoped to lift small registration devices like thermometers etc. into the upper atmosphere for meteorological research work. He chose a machine "heavier-than-air" because at those times flying machines "lighter-than-air" were not yet in practical use.
From its basic layout the machine was a helicopter with two coaxial two-blade rotors. The rotors were driven by a clock spring. On 1 July 1754 Lomonosov demonstrated his machine at the Russian Academy of Sciences. For this demonstration the machine was attached to a thin rope running through two rope pulleys and hold in equilibrium by small weights at the rope's other end. As soon as the clock spring had been wound up, the machine climbed upwards, demonstrating that the basic principle was working.
According to the inventor the machine had been constructed to develop a lifting power of 9-10g. But despite the small size of the apparatus this was not enough to enable it to fly freely, let alone with an additional payload. Lomonosov was nevertheless convinced to be able to enhance the lifting power by using a stronger clock spring, enlarging the diameter of the rotor blades and simultaneously reducing the machine's weight by making its spring casing from wood. He promised to do so, but due to much other research work this was never realised.