Blue Lantern is an artifact that is commonly seen in The Rift. It makes appearance in several stories that are set in and around The Rift, and later in Eremidia: An Empty Tome. Its primary function revolves around Great Library's functionalities. The lantern is also functioning as proof of Library membership.
Blue Lantern is a simple construction made from bronze, resembling palm-sized oil lamp with a distinctive blue-ish color on most of its surfaces. The lamp shines its shimmering blue light, suspended on a small platform at the base of the inner side of the lantern. The suspended matter inside the lantern is a purified ether sourced from the well at the basement of Great Library; the ether becomes integral part on most of the lantern's functionalities around Library's facilities.
While its original name is lost to the history, the name “blue lantern” is a common name addressed to the artifact due to its appearance and its most basic function.
The first lantern was built by an unknown race of primordial age, given to the Grand Archivists who were assigned into a task of maintaining the Library in its early ages. After several times of failed attempts in replicating the relic, Grand Archivists were eventually able to replicate the lantern and created many more lanterns of similar functions and uses for both Librarians and those registered in Great Library's member list.
Blue Lantern's primary function is to aid those who wander through the vast collection of the Library by providing light adequate enough for reading in murky places at the corner of the study. Later on, its other functions revealed by either the Librarians and the visitors of the Library, such as: