|Offers some suggestions on Mackenzie Davidson's invention [cross thread localiser]. Notes that, at present, one has to mark the position of the x-wires on the patients body by hand. Suggests instead that a small hole is drilled into one of the cross wires, an india rubber bulb is fixed to it and the wire is filled with the ink. Then all that has to be done is to squeeze the india rubber bulb which will allow a drop of ink to issue from the hole to directly under the cross wires on the patient. Also makes suggestions for the method of measuring the depth of the bullet from the patients skin. Includes an illustration of how this might work.