This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
Dibbers and trowels are well-known instruments for the removal of plants of various kinds. In using the pointed or semicircular trowel, the young plants may be taken up with a considerable ball of earth attached to the roots, while they suffer no injury by the process. A more perfect mode of transplanting by the [use of the trowel, is that by taking two of these, one in each hand, thrusting them down on opposite sides of the plant, at the same time drawing the handles slightly outwards; the faces of the trowels are thus made to collapse so much as to press the soil about the roots, and enable the operator to take the plant, with ball entire, from the seed-bed to its destination, and to place it in its new abode without the least check to its growth. We have figured several transplanters, which have been employed for such plants as the brassies, etc. Fig. 1 is called Saul's transplanter. It may be thus described: The blades are opened by pressing the lever, a, towards the handle, when they open outwards, and in this state are thrust into the ground, having the plant within them; a counter-pressure causes them to collapse and embrace the bail firmly, and, in this state, the instrument being drawn upwards, brings with it the plant and ball entire; it is then taken to its new place, when the handle is again pressed inwards, and the blades open and are withdrawn, leaving the ball to be filled around with earth.
Fig. 2 shows a modification of the above instrument, wherein the blades are opened by moving the slider, a, upwards, and when thrust down around the plant, the blades collapse by pressing the slider downwards. The operation, afterwards, is the same as in Fig. 1.
Upon the same principle, but with much more mechanical intimity, is McGlashan's trarusplanter, Fig. 3, constructed, which is admirably adapted to such operations. These three collapse upon the ball firmly - and not only that, by their construction they embrace it tighter at the bottom than at top, rendering It next to impossible that the ball should be extracted, and, also, that it cannot slip out afterwards until relieved by the removal of the pressure upon it. All these transplanters are merely modifications of Fig. 4, long used, in France, for similar purposes. Its principle will be readily seen by the figure. The handles, a a, are pulled outwards when the blades are thrust into the ground. They are pressed inwards when the operation of lifting upwards is desired.