| 摘要 |
An irrigation signal which has a cylindrical body to receive a cylindrical elongated float, the body having an upper portion and a lower portion, the lower portion being adapted to extend below the bottom of the irrigation ditch in which it is installed in order to form a well in which irrigation water may enter in order to raise said float a substantial distance above the top of the ditch to signal that irrigation water has been present or is present in said ditch. The irrigation signal has a removable plug at the lower end of the body so that when the plug is in place irrigation water will be retained in the body and keep the float in a signalling position, or in which, when the plug is removed, the water will drain from the lower end of the body so that the signalling float will be in signalling position only when there is water in the irrigation ditch.
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