Gregorian telescope [SEP] named after
Gregorian telescope
The Gregorian telescope is a type of reflecting telescope designed by Scottish mathematician and astronomer James Gregory in the 17th century, and first built in 1673 by Robert Hooke. James Gregory was a contemporary of Isaac Newton, both often worked simultaneously on similar projects. Gregory's design was published in 1663 and pre-dates the first practical reflecting telescope, the Newtonian telescope, built by Sir Isaac Newton in 1668. However, Gregory's design was only a theoretical description and he never actually constructed the telescope. It was
is 7 x 7 years in length. All these time units share the number of seven or weekly cycle. Every unit is named after its first day, which is also the last day of yearly and 50-day cycles.
The first 50 days of the Somali Calendar Year of 2007-2008, in the Gregorian system, are from Saturday July 21, 2007, to Saturday Sep. 8, 2007. The same pattern applies to the first and the last days of the year, "while the first day of the year