If the system of management requires requeening during a fall honeyflow and there are several frames of brood in the upper brood chamber, this may be separated from the main brood nest below by the insertion between them of a temporary combined bottom board and cover which gives a rear entrance to the upper story. The old queen remains in the lower brood chamber and in the upper one is placed a choice ripe queen cell. Next day the virgin emerges. She soon mates and establishes a new brood nest. Both stories become filled with honey and the double colony may be wintered in that condition. Removal of the combined bottom board and cover in the spring will unite the two colonies; and the colony, now having a young queen, is in standard spring condition and should reach standard honey-storing strength at the beginning of the honeyflow.

In this double brood chamber system, two ten-frame Langstroth hive bodies containing choice dark all-worker brood combs, are reserved for the use of the queen and for winter stores.

Less time is required in management than when only one Langstroth brood chamber is used. Considerable good pollen is likely to be stored in these frames for spring use. The storage of pollen is important, because, for the best breeding conditions, much pollen may be required long before favorable weather permits the bees to gather enough from spring flowers. None of these twenty-brood combs are ever used in the supers, which may, therefore, contain all light-colored extracting combs.

Nor is it ever necessary to crowd into the brood chamber, for winter stores, thick, heavy combs of honey from extracting supers in which only eight or nine frames were used. The fine old brood combs of the double brood chamber which never go into the extractor, are not injured as extracting combs so often are, and therefore remain useful for brood rearing much longer. Little pollen gets into the extracted honey when this plan is used because bees store pollen chiefly in combs adjacent to brood.

Shallow super frames having wide end bars, and spaced nine in a Langstroth 10-frame super are easily handled and transported without damage and leakage. These combs are kept white and free from brood and pollen and in condition for producing honey of the finest quality. They are admirably adapted for use in clear brood nest systems in which queens are never permitted to lay eggs in the supers.

The use of a two-story brood chamber all the year round should be more common.

It is satisfactory for the production of comb as well as extracted honey. With less man labor it gives results equal to those attainable where the Langstroth one-story clear brood nest system is used; and, owing to the abundance of room available for the brood nest, congestion, crowding, unbalanced conditions and consequent swarming are more easily controlled. It also simplifies the control of American foulbrood because if queen excluders are used no diseased brood can ever be elsewhere than in the two brood chambers;

Under this system bees need but little attention as far as winter stores are concerned, because the upper story, toward the end of the honeyflow, becomes practically filled with good sealed honey. Some users of this plan bore a hole with an auger in the front of the upper story for winter entrance and keep the lower entrance closed until spring. The bees can control such an upper entrance readily, as they will have worked into the upper story for winter. The auger hole cannot become clogged even if many bees die during a time when they cannot be carried out.

While the amount of honey produced under this system does not exceed that obtained where a Langstroth one-story clear brood nest system is used, expert care at short intervals is less necessary. An extra hive body with a set of brood combs is, however, a necessity for each colony in order to provide it with a two-story brood chamber.