Evolution Bike

To the source of a bicycle can, apparently, include permutation wheel carts with two-track position in the single track. At the end of XVII century in many countries, there were wooden single-track two-wheeled carriages, which were set in motion by the rider - he took it down the ground, and thus moved to the top of the carriage. These were the first prototypes of the modern bicycle. A typical example of such crews can serve as a "toy horse" Charles Dries, based on single-beam scheme. The self-name of the crew talks about entertainment vehicles, do not pretend to convenient means of transportation, the steering wheel is not yet available. No wonder such crews called "kostotryasami."

On the verge of the XVII and XVIII centuries, "kostotryasov" appeared swivel front wheel ensures rule balansiovanie. An example of such personnel may serve as a "scooter" Blanshera.

Two-wheeled scooters of this type began to fight for speed, reliability and security: the wooden wheels appear with metal rims, riders are provided with a special metal-lined shoe keeps your feet from injuries at the wheel scooters attach "gun" to scare the dogs.

1801 is officially the year of bike - two - three-wheeled personal vehicle, driven by the feet of man sitting on it. That was the year the Russian working land EM Artamonov (1776-1841) demonstrated in Moscow on his "scooter with pedal power to the front wheel." On this scooter, made of metal, Artamonov came from the Urals to Moscow, made the journey of more than 1 km. For this invention Artamonov and his descendants have been released by the government from serfdom.

History of the chair

By analogy, we can safely say that the chair - is brilliantly edited stump.

The evolution of the stump as the subject to sit is relatively easy to follow, when a person is not able to make furniture, as chairs were stumps, logs, stumps logs log. Then there was a stool. Stool with back called "chair", and chair with arms was called armchair. Evolution stump over.

How many chairs a man need?

The question is not idle. And to answer it, not taking into account the requirements of the time, it is impossible. Now, as the statistics show, for one man, half a dozen chairs are enough: at least one chair at home for themselves, the two - for guests, one chair at work, another chair at work for a possible visitor, one chair at the holiday destination.

The practice shows that we especially require a lot of chairs at home.

Simple arithmetic dictates that for the six millionth Moscow need at least 60 million chairs, and for all the people of our country - almost astronomical number.

Chairs mostly made of hardwood - beech, oak, beech and birch. The best chairs, including the famous Viennese are made of beech wood. One chair requires about 0.02 cubic meters of wood. That is to say, "clean out". If you add on the fact that a thing of the chip, it turns out that every chair "eats" 0.06 cubic meters of wood. Only in 1971 in one country was made about 42 million chairs. Their production took over two and a half million cubic meters of wood!

Well, the chairs are not for a year or two, and they are not making me feel like a glove: otherwise they would be "eaten" all the forests. However, they have "eaten" many: beech is almost gone, and bentwood furniture, which can be done only in beech, now is very rare