The Iram Solis (also known as the Inferno Mask ✣ ) is a Sparky object used to massively boost a dragon's internal flame. It is mentioned in a Girl Genius side story called The Quest for Gold and Sequels. The Spark who created it is unnamed in the story and the exact reason it was created is unknown, but circumstantial evidence suggests that it was made by the same Spark who created Hydrargyros, the Godburner, a dragon, to make up for the fact that Hydrargyros' flame was so weak. Unfortunately for that Spark and the populace at large, Hydrargyros, who by all accounts was a nasty customer, used it to cause mass destruction, creating the Dragon Wastes and quite possible killing his creator in the process.
Hydrargyros holding the Iram Solis. (The sepia tones are because the image is from a segment of the story told in flashback.)
Semi-rogue Librarian Vipsania Perrault discovers evidence that leads her to believe Hydrargyros has died and his hoard, which includes some very rare books as well as more conventional treasure, is up for grabs. She recruits Franz Scortchmaw to help her get into Hydrargyros' lair and together they travel to loot the hoard. Several others join their party, including the Corbettite Monk Brother Marcus, who believes the Iram Solis is part of Hyrargyros' hoard and wants to secure it before it can fall into the wrong hands. The party meets Professor Blintzie von Wyrmhaut, who is already at Hydrargyros' lair but hasn't been able to enter it, and who is seeking the Iram Solis for her own benefit. (Professor von Wyrmhaut could easily be the poster girl for "the wrong hands".)
Once the party finally manages to find a way to enter the lair, Blintzie spends most of her time frantically searching for the Iram Solis, to no avail. After a long and complex sequence of events, most of the party ends up battling a Fun-Sized Mobile Agony and Death Dispenser guarding the hoard and they are faring poorly against it. Franz, who seemed to have abandoned the rest of the party and fled, ✣ unexpectedly reappears and uses the Iram Solis to destroy the clank. ✣ Franz reveals that while Blintzie had seen the Solis as a treasure, it was actually a tool, something that you'd want to grab fast on your way out of the door. As such, Franz had found it ✣ out in the hall on Hydragyros' coat rack.
Blintzie manages to get her hands on the Solis and escape, but according ✣ to a later-glimpsed Mechanicsburg newspaper headline, her attempt(s) to use it literally fizzle for unexplained reasons, possibly because she has no dragon to help her. As a result, Blintzie is publicly disgraced.
Possibly relevant outside information[]
According to Google Translate, "Iram Solis" means "Wrath of the Sun".