Chromium-vanadium steels are the latest development in structural alloy steels that have gained an extensive market. Almost all these steels are made in the open-hearth furnace; the chromium and vanadium alloys being added shortly before casting. In their physical properties these steels are much like chrome-nickel steels, but they have a greater contraction of area for a given elastic limit than the latter. The greater part of the chrome-vanadium steels made goes into automobiles. Some manufacturers prefer such steels because of their greater freedom from surface imperfections, notably seams, which steels containing nickel are prone to have if the ingots are at all unsound. These steels are almost always used in the heat-treated condition, but even in automobiles some frames, forgings and shafts are made of the steel in its natural state. Some chrome-vanadium steel is said to be used in armor plate of medium thickness, which is not face-hardened but has high resistance imparted by heat treatment. Vanadium is also used to some extent in making bronzes, in medicine and in dyeing. =Substitutes.=--Several substitutes, chiefly titanium and molybdenum, have been claimed to give the properties of vanadium in steel. Both of those metals give to steel some of the properties that are usually associated with vanadium, but neither one takes the place of vanadium entirely. CHANGES IN PRACTICE The Primos Chemical Co. (see later) has its own patented method for treating roscoelite, the ore found at Newmire, Colorado. This method consists in roasting the ore with salt containing a little pyrite, and is a method that is applicable to some extent to most vanadium ores that do not carry lead. The American Vanadium Co. has a secret process for the treatment of its Peruvian ores. This method has not been published. The treatment of vanadinite, cuprodescloizite and carnotite ores has been studied by the U. S. Bureau of Mines, at Golden, Colorado. Whatever change in practice takes place is likely to be mainly in the concentration of vanadinite and in the treatment of this mineral and cuprodescloizite. GEOLOGICAL AND GEOGRAPHICAL DISTRIBUTION