Bastin, E.S. and Davis, C.A. 1909. Peat deposits in Maine. U.S. Geological Survey Bulletin 376. 127 p.page 61
A lighter and better form of sampling tool, devised by C.A. Davis, is so constructed that samples can be obtained from any desired depth without danger of contamination. It consists of a short metal cylinder, sharpened at its lower rim, into which fits a metal plunger long enough to fill it completely. The upper end of the plunger is attached to a gas pipe similar to that used in the apparatus previously described. (a ship's auger) The plunger is provided with a spring catch so that it can be partly withdrawn from its inclosing metal cylinder and locked in that position. In collecting a peat sample the plunger is inserted in the cylinder so as to fill it completely and the apparatus is pushed down into the peat nearly to the depth from which the sample is desired. It is then given a short upward pull, which serves to withdraw the plunger from the inclosing metal cylinder. The apparatus is again pushed down, and the spring clamp prevents the plunger from reentering the cylinder, which becomes filled with peat. The apparatus may then be withdrawn from the bog and the sample ejected from the cylinder by again forcing in the plunger. The cylinder protects the sample completely from any mixture with other peat during withdrawal.