Some thing about Abacus the first calculating device

Now let we start from the abacus where we ended. Later on a little development was made by John Nappier who made Napier Bone which were made by the bone of the some animal. In which numbers were stroked. A mathematician Herman Hollerith developed the tabulating machine that used to do some simple calculation like addition, subtraction and multiplication. Later on many other calculating device were invented. The first computer which was invented by John Von was Mark 1st. It was too bigger in size and used to use large amount of space and mile of cables. It used the valves or Vacuum tubes as its main component in it. It even used large capacity of the electricity. It consumes a full room space and two many man power to use it. The main component vacuum tube was invented by Lee Dee Forest during the period of 1956 to 1963 AD. This was something about first generation computer.