History of Telescope
Telescope is the one of the great invention of all. It makes men powerful to see the distant object clearly. It was one of the great revolutions of seventeenth century, though there is some documents available who shows that its concept is of before 17th century but there is no any clear design available. It is also consider that telescope is the invention of craftsman but they were illiterate so no proof available. It often becomes the part of controversy between followers of geocentric astronomy and of heliocentric astronomy.
The news about the discovery of such kind of instrument came in to existence in 1608 by Hans Lipperhey of Middelburg, he came to patent this instrument and later this was attempt by Jacob Metius of Alkmaar. This news was like a fire in Europe. In 1609, three powered spyglasses were in market by Pont Neuf in Paris. And later it was available in Italy. But we consider Galileo as the father of Telescope because this device famous. He constructed and presented eight powered instrument in August 1609 and made 20 powered instrument. This instrument was capable to observe moon and satellites of Jupiter and some stars patches. Since there were no sufficient instruments available at that time so initially it was difficult for everyone to see some lunar or other details of distant object. But there were some short coming of this telescope: firstly it having small field of view i.e. about 15 arc minutes and also polish was poor.
With the time many new inventions made in telescope, high quality polish was made, and Galilean telescope of higher magnification were made but because of concomitant shrinking of the field.
The Galilean telescope could be use for the both purpose i.e. terrestrial and celestial, but after 17th century the Galilean telescope was replaced for terrestrial purposes by the terrestrial telescope, which had four convex lenses known as objective, ocular, erector lens, and a field lens. In the starting of 1640s, the length of telescope was increased. Galilean telescope was of 5 or 6 feet but astronomical telescope was of 15 to 20 feet. Magnification power of astronomical telescope was about 100 times. But long telescope were not worth for observation. After 1675 astronomers started using pole by means of ball-joint and aimed by means of a string. Many high quality telescopes were designed in the middle of eighteenth and 19th century. Now a day every type of telescope is being available in market.