I have thought that the word _verso_, used technically for the reverse of a coin or medal, might be usefully employed in dactylography for the reverse or mirror image of a finger-pattern when printed. A technical word for the indented impression made by a finger on wax and the like is also wanted. Now geologists use _-lite_ as a terminal to express the impression or cavity which had been formed in a rock, when soft, by the impressed body of an organism. Hence the word _dactylolite_ might be used to denote an indented impression of a finger. [Illustration: KEW MICROMETER.] In making measurements of exhibits, the Kew micrometer devised by Sir Joseph Hooker is of much service. It is figured here, and has the useful quality of rendering measurements at the same time in both the English and decimal systems. For the method of encircling suspect smudges, either before or after enlargement, and measuring from one fixed centre by the Kew micrometer or ordinary compasses, I have devised a disc of glass such as is used in microscope slides, and about the size of half-a-crown. In the centre is a conical pit into which one leg of the compass rests. Precise centring is thus obtained without the slightest risk of damaging the photographic or other exhibit by the sharp point of the compasses, which have, at the same time, free swing. These were prepared for me by Mr. Franks, optician, Stoke-on-Trent, and cost very little. [Illustration: GLASS DISC CENTRED (enlarged).] In all measurements close to a fork or junction, as in the crook of the letter =Y=, care must be taken in counting the lines below or above the fork. Ambiguity readily arises, with a train of resulting discrepancies. Other ambiguities also occur which require mention in a word or two. In deciphering an ancient manuscript blurred, mouldy, mayhap worm-eaten, doubts may arise as to which of two or three possible words or letters may have been intended. One looks for some rationality in the author’s writing, but in finger-prints there can be no such help. In manuscripts the problem may not directly be as to a word, but only as to a letter, but that single letter, read differently, may change the tenor of a passage. Is ={deformed G}= to be read as =C= or as =G= or as =O=? Is ={deformed E}= to be read as =E= or as =B=? So Fork is liable to be read as Pork.