Science is not a forgotten lore to the Empire if Tulath. Magic is mainly just used to bolster the prevailing science. Like the trains that use the superheated metal to create the steam required. In fact, the factories were dirty affairs but have cleaned up significantly. This was found out after the Church of Man discovered that magic failed to work when it got 143.62 kilometers above the surface of the planet. Nothing could change the fact that everything stopped working when it got to that height. If they wished to return to the stars, they would have to use science.
The Tech-Priests have done a lot of for the Empire of Tulath. They have saved their society from barbarism and strengthened it to be a dominant force. That is not all the Church of Man does however. They have terrible weapons of mundane, magic and science-make within their vaults. They are now searching the world for the portals that brought the eladrin here from a distant planet, thinking that if they could recreate the journey that eladrin took, they could find their way to Terra and eventually home.