ture. A large part of the United States has too high a temperature. Where the temperature is high beets grow luxuriantly, but they contain a small percentage of sugar. On the other hand, where frosts come early in the autumn, the beets can not arrive at maturity. Other things being equal, the farther north the beets can grow to maturity the greater will be the sugar content. In 1897 the Department of Agriculture gave as a provisional area a zone having a mean temperature between 69 °F. and 71 °F. for the months of June, July and August. This forms a strip across the country sometimes very narrow, sometimes quite wide—in New Mexico and California running south of the thirty-third parallel of latitude, in Dakota north of the forty-sixth, forming on the map a serpentine band which, owing to its many folds and twistings, has a length considerably greater than double the width of the continent. In addition to this belt there are a few outlying areas as for instance a portion of Washington. The belt begins on the east in the neighborhood of New York City, and on the Pacific it forms a long strip stretching between four and five hundred miles, almost due north and south, and extending to the Mexican boundary. Later investigation has widened this area a little, chiefly on the north, but has not very materially affected it. It must not be supposed that all parts of the belt are equally favorable. For instance, though North Dakota and southern California have the same average Temperature in June, July and August, in the former place frosts come very early and the winters are severe, while in the latter there is little frost at any season.
The rainfall is a matter of importance. Warm rains in the early part of the season and dry weather during the period of maturing are best. In arid districts, irrigation may be resorted to, and has the great advantage that the supply of moisture can be regulated. Irrigation works are usually expensive and do not ordinarily pay in the raising of cereals, but the sugar beet is a valuable crop and experiments already made point to the probability that Colorado, Utah, New Mexico and other similar states will become extensive producers of sugar beets. Ten million acres of arid land could be irrigated comparatively easily and that would more than supply the world with sugar.
The growth of the sugar industry in Michigan is very interesting. In northern Michigan lumbering has been carried on very extensively for a number of years. The result is that the timber areas have been rapidly denuded. The question as to the use to be made of the land from which timber was removed became pressing. The soil was considered too sandy for ordinary agricultural purposes but it turns out to be very suitable for beet culture and sawmills are being replaced by sugar factories.
The sugar is not the only valuable part of the beet. When the juice