Chemical granule sprayers
The photograph is courtesy of Inverness, Ross and Skye Forest District and staff at their Fort Augustus office.
This photograph may have been taken around Speymouth Forest Office and shows three type of chemical granule spreader being tried out at that time. The application of granules of herbicide was much easier that of using liquid sprays but evenness of spread and dosage rates were very difficult to control in the field. The two sprayers on the left were developed by manufacturers while the third on right was pioneered by Chief Forester Davy Anderson from Clashindarroch Forest. The design of dosage pistons effected an improvement in dosage rates but the mechanism could jamb up and if the applicator discharge tube and spread cone were not held near vertical, herbicide application could be heavy on one side of tree and of limited value on the opposite side.