Spa
2 of the 7 encyclopedias on this shelf carry an entry for Spa. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
or SPAA, a town of Belgium, and a watering place of world-wide celebrity; in a romantic valley amid hills which form part of the Ardennes chain, 27 miles S. E. of Liege, and 22 miles S. W. of Aix-la-Chapelle. The prettily-built town consists almost entirely of inns and lodging houses. The mineral springs are efficacious in complaints of the liver, nervous diseases, dyspepsia, etc. Spa water is exported to all quarters of the globe. Spa is also famed for the manufacture of wooden toys, which are stained brown by being steeped in the mineral waters. It was frequented as a watering place as early as the 14th century, and has given given its name to many mineral springs. Here the German Great Headquarters were established in 1918, where consultations were held concerning the armistice and from whence the German delegates set out for the French lines to meet Marshal Foch and sue for peace.
Aiton's Encyclopedia (1910)
spa, a town of Belgium noted for mineral springs. It is situated in a beautiful valley of the Ardennes about equally distant from Liege and Aix-la-Chapelle. The town is a center of toy making and other small industries, but is composed largely of hotels, baths, and other accommodations for guests. The springs, several in number, furnish a cool, sparkling water, impregnated with alkaline salts, carbonic acid gas, and a trace of iron. Spa water is celebrated as a remedy for nervousness, dyspepsia, and liver complaints. Immense quantities are bottled for export to all parts of the world. Wooden toys dipped in the water take on a tan color. The term spa is now of general application to mineral springs elsewhere. See Waters ; Sulphur Springs