Two Ships 2nd Edition

Two Ships is a story from the "Illustrated Tales From An Alternate Steampunk History" series. According to Alternate History, in the early 1800's, inter-dimensional experiments were conducted in an effort to create a transportation portal that would allow a person, in an instant, to literally step from one place to another that was thousands of miles away. Not long after the experiments began, there was an accidental side effect of being able to step backward or forward in time as well. Shortly after this side effect was discovered, all time related experiments were discontinued out of fear that the very fabric of History could be destroyed. In addition to time, there was another dangerous side effect. Sometimes when a portal was opened, (in addition to the intended destination time and location), other doorways would open at random, allowing for something unintended to pass through. This was the case with a balloon ship from the 16th century and a starship from the 19th century. They both departed from America centuries apart. At first, both Captains where completely unaware that their destinies were interconnected until one of them learned of their encounter from illustrations in a children's book in his ship's library. Two Ships is also the story that reveals part of an Old Russian legend that tells of a powerful shadow empire that once existed deep in western Siberia. One of the captains quickly realizes that in order to survive, they have to help each other, and at the same time see to it that the events of their encounter unfold in such a way as to not alter history. It turns out that one of the ships was intentionally pulled through a time portal and the other was accidental. The question is" By whom and why?