From G. Donald Adams book "Collecting and Restoring Antique Bicycles" - "Introduced about 1893 by the St.Louis Refrigerator and Wooden Gutter Co., St.Louis, Missouri, the Lu-Mi-Num bicycle was cast hollow in one piece. Containing a small percentage of alloy, this bicycle evidenced a very early use of aluminum. The front fork was cast solid and all was polished, but not to a mirror finish.
Rights to the manufacture of the Lu-Mi-Num bicycle were purchased by M.M. Cycles, Sans Souderes en Lu-Mi-Num who manufactured it in Paris. It was sold in England by the Lu-Mi-Num Mfg. Co., Ltd. of London.
Lu-Mi-Num's 1895 ladies and gents models weighed 25 lbs. and sold for $125. At the 1895 Chicago Bicycle Show, a Lu-Mi-Num exhibit provided for testing the strength of the aluminum handlebar. Two heavy men were permitted to suspend their weight from either side to show that it would not bend or break. Samples of the aluminum used in making the bicycle were twisted and bent into every conceivable shape without fracturing. A gauge demonstrated the perfect alignment of the Lu-Mi-Num frame, which was claimed to be truer than any steel frame.
A chain case integrally cast with the frame, gave extra strength to the 1896 model. Today Lu-Mi-Num bicycles must be ridden with care to guard against fracturing due to age and embrittlement of the aluminum."
There is an illustration of the 1896 model with the chain case in the book.