Fig. 9. Hitterdal-kyrke. This church, which is built of wood, has stood in this smiling valley for nearly 700 years. Note that the bell tower is across the road from the church.
construction which will furnish sulfuric acid as a by-product. In many cases it has proved simpler to use the cyanamid itself directly as a fertilizer, letting the moisture of the soil convert it into ammonia as needed. On many soils the nitrogen of the cyanamid is found to be equally efficient with that of ammonia or of nitrate, while on other soils it has less value. Its use has, however, become established and we may look for the installation of cyanamid plants in many places where water-power is cheap. A plant on the Canadian side at Niagara Falls is already in successful operation.
A word regarding the power of the Odda plant may not be amiss, as it illustrates the resources of Norway in this line. The power plant is at Tyssa, some four miles distant from the cyanamid works. The water is brought down to the dynamos in two pipes of rolled steel 12 inches thick and about two meters in diameter, with a fall of 1,450 feet, developing 22,000 horse-power for the cyanamid and carbid works. This is shortly to be increased by raising the level of the water supply, and it is said that there will be a development of 125,000 horse-power. The current is transmitted from the power house at 11,400 volts and is stepped down to 75 volts for the cyanamid manufacture and to 400 volts for the liquid air plant.
Another, and even more important effort to solve the problem of manufacturing nitrogen fertilizer from the atmosphere has been the attempt to convert the nitrogen of the air into saltpeter. It has long been known that when an electric discharge is passed through air, the