I came across a Monomelt in Itasca, Texas about ten months ago. I picked up a couple little books about it on my friend eBay. Here is a description from one of them:
"Monomelt offers a convenient, efficient system of handling type-casting metal with a single melting process. This compact, handy unit, which feeds molten metal to the melting pot of a type-casting machine, is more than an auxiliary pot. It represents an entirely new, modern method of supplying cleaned, refined metal at exactly correct temperatures for casting sharp, solid type.
"Fundamentally, Monomelt is an electric or gas heated crucible which melts, and cleans metal, then feeds it automatically to the regular pot of the type-casting machine.
"However, its sphere of operation takes in the entire shop. The Monomelt System takes complete charge of the metal from kill-out to freshly cast slug. It abolishes the melting furnace with its metal pigging process, and spells savings in time and labor for the entire composing room. It improves production and quality of type, and reduces dross loss and metal inventories.
"How the Monomelt Works
"Dead metal, trimmings and type are emptied directly into the Monomelt hopper. As the metal melts, sensitive heat governors maintain constant temperatures in both the upper and lower pots. A graduated indicator allows a setting for any desired temperature, and one set, it never varies. The Monomelt feed valve with float control supplies metal at the ideal casting temperature through the bottom of the Monomelt crucible into the machine pot. A constant metal level is maintained regardless of the size of the slug cast or the rapidity of casting."
It goes on and on, but that's most of the first page.