File:Apple pollination studies in the Annapolis Valley, N.S., Canada, 1928-1932. (1933) (19557918918).jpg

Title: Apple pollination studies in the Annapolis Valley, N.S., Canada, 1928-1932.
Identifier: applepollination162brit (find matches)
Year: 1933 (1930s)
Authors: Brittain, W. H; Canada. Dept. of Agriculture
Subjects: Apples; Fertilization of plants by insects
Publisher: Ottawa : Department of Agriculture
Contributing Library: Agriculture and Agri-Food Canada – Agriculture et Agroalimentaire Canada
Digitizing Sponsor: Agriculture and Agri-Food Canada – Agriculture et Agroalimentaire Canada

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120 used. There are four different circuits in the hook-up. The primary circuit is that of the photron cell. This is connected with a Weston Model 30 relay (fig. 1, C). As the bee passes through the tunnel (fig. 2, K) it interrupts the light beam passing through the slits Q and R and falls on the cell B. This interruption varies the potential in the circuit and operates relay C. Operation of this relay causes completion of the secondary circuit, a 4^-volt direct current supplied by three dry cells (fig. 1, H). This current in turn operates a second relay (fig. 1, D), which acts as a switch in the 110-volt alternating current line, and operates the counter (fig. 1, E). The fourth circuit has an eight-volt, alternating current obtained through a transformer from the 110-volt line. This supplies the power to a 32 candle-power bulb, such as is used in the ordinary automobile headlight.
Text Appearing After Image:
Fig. 55.—Diagram of photo-electric bee counter. (A) 8-volt, 32-candle power bulb; (B) Weston photron cell; (C) Weston model 30 relay; (D) secondary relay; (E) elec- trical counter; (F) transformer; (G) knife switch; (H) battery of three dry cells: (I) cone-shaped lamp box; (J) Abbe condenser; (K) tunnel (exit) ; (L) tunnel (entrance); (M) landing board; (N) bracket supporting light; (0) adjustable bracket for light socket; (P) concave mirror; (Q) slit in roof of tunnel; (R) cover slip over hole in floor of tunnel; (S) celluloid trap door at mouth of tunnel (original). Figures 2 and 3 show the essential details of the hive unit. Figure 3 is a front view, and figure 2, a cross-section. The landing board is cut off flush with the inner face of the front of the hive, and the unit substituted. The entrance is divided into a number of tunnels about three-eighths of an inch square, and approximately three inches long. These are closed at alternate ends by a trap-door, so that passage is possible in only one direction. The material used for the trap was ordinary photographic film hung on two narrow hinges of cello- phane. These hinges had to be renewed quite frequently, as the bees often gnawed them off. The light was enclosed in a cone-shaped guard directly over

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