Fluorescent lamp began with the Geissler tube continued as even better vacuums were produced. The most famous was the evacuated tube used for scientific research by William Crookes. That tube was evacuated by the highly effective mercury vacuum pump created by Hermann Sprengel. Research conducted by Crookes and others ultimately led to the discovery of the electron in 1897 by J. J. Thomson and X-rays in 1895 by Wilhelm Roentgen. But the Crookes tube, as it came to be known, produced little light because the vacuum in it was too good and thus lacked the trace amounts of gas that are needed
The Amazing Race en Discovery Channel 2 January 2010 and filming took place between May and June 2010. The show was to be broadcast in high-definition television. Filming for the second season of "The Amazing Race en Discovery Channel" lasted for 25 days and covered nearly . The second season spanned eight countries in two continents. Among them, 4 were unvisited countries, including Bolivia, Guatemala, Ecuador and Venezuela. Previously visited countries were Mexico, Brazil and Argentina. Colombia was also a previously visited country never visited in the original American version at the time of air, it will later be visited in the twenty-eighth season in 2016. The