The Orb was a mysterious, powerful artifact sought by John Bly.
According to time-traveler Karina, the Orb was "a man-made electromagnetic wave particle net that capture[d] energy at certain nodal intersections of the space-time grid." There were actually three different Orbs that were sent back in time from the year 5502, in order to aid the advancement of mankind.
John Bly Edit
John Bly, himself a traveler from the year 2506, wished to possess the Orbs in order to gain the power to rule the world. He came to 1893 to seek the artifacts, as that was the year that all three were known to be found at the same time.
Fate of the Orbs Edit
One Orb was damaged and ended up self-destructing. The other two were taken back to the future by Karina.