On the Canadian side of the Niagara River are three great power plants which are now generating about 160,000 horse-power; but which will ultimately develop nearly 400,000 horse-power. The Canadian generators are of much greater capacity than those on the American side and develop from 10,000 to 12,500 horse-power each. Two of these plants are built over wheelpits like those described on the American side and one of the companies in order to release the water used in its turbines has constructed under the Niagara River a tail race tunnel, the portal of which discharges directly beneath the Horse Shoe Falls.

The Ontario Power Company by erecting a power-house at the level of the lower river and near the foot of the Horse Shoe Falls and by

conveying water through an eighteen-foot conduit from an intake canal above the falls has obviated the necessity and the great expense of building a wheelpit for the utilization of the water pressure and has acquired for its turbines practically the full head of water between the upper and lower rivers, a difference in level of approximately 175 feet.

Directly above the Ontario Company's power-house the great eighteen-foot conduit is tapped by penstocks nine feet in diameter which convey the rushing water to the blades of the turbines. The generator attached to each turbine is thereby caused to revolve at the rate of 1872 revolutions a minute. Each generator weighs 231 tons and develops an alternating current of 10,000 to 12,000 horse-power at 12,000 volts, much of which is transformed to a voltage of 60,000 and transmitted with comparatively small loss over aluminum cables to Rochester, Auburn and Syracuse, a maximum distance of 160 miles.

The uses to which electrical power is put in the city of Niagara Falls are most interesting. In 1886 Charles M. Hall, at the age of twenty-two and fresh from Oberlin College, devised a process for the inexpensive production of aluminum. Prior to Mr. Hall's discovery aluminum though the most abundant of all metals was united to other elements in such a way that a separation of the metal from its compounds was very difficult and correspondingly expensive.

Mr. Hall's process for obtaining aluminum from its ore is a reduction or deoxidation process by electrolysis. Into a carbon lined vat or "reducing pot" extend carbon cylinders. The vat is partly filled with powdered cryolite, a beautiful white mineral mined in southern Greenland. When the electric current passes, the resistance

to the passage of the current offered by the cryolite transforms into heat sufficient electrical energy to fuse the cryolite. Into the fused cryolite is poured calcined and purified bauxite in powdered form. The oxygen of the purified bauxite combines with the carbon of the anodes or positive poles of the electrolytic cell to form carbon monoxide and carbon dioxide gases and the aluminum is withdrawn in an almost chemically pure state. Since the cryolite serves merely as a solvent for the bauxite from which the aluminum is obtained and is unaffected by the electric current, the reduction of bauxite is continued indefinitely by pouring into the reducing pot enough bauxite to supply the place of that reduced.

Another electrolytic process in use at Niagara Falls is the production of caustic soda. The demand for caustic soda in many industries such as soap-making and paper-making is so great that an inexpensive way of producing this important alkali is imperative. The process is

comparatively simple. Into an electrolytic cell is poured common salt in solution. When the electric current passes through the brine the salt is separated into its constituent elements, chlorine gas and the metal sodium. The chlorine gas is evolved at the anodes of the cell and being led off combines with slacked lime to form chloride of lime or bleaching powder. The sodium unites or reacts with water to form sodium hydroxide or caustic soda.

When Moissan, the great French chemist, perfected the electric furnace he gave to scientists an easy way of producing a temperature which far exceeds that of ordinary fuel and even that of the oxyhydrogen flame, and which made possible new and useful combinations and dissociations of matter obtainable in no other way than by the use of intense heat. The electric furnace is used at Niagara Falls in the manufacture of several new and important products.

Among the many recent discoveries in the field of electrochemistry