Here is my latest treasure from David Penney: a watch movement with a true chronometer escapement, signed by (or rather for) James Hatton who practised alone between 1805 and 1816. The balance is of the form developed by Robert Pennington, and I understand that the detent of the escapement is also of a type specific to him; for these reasons, and perhaps others which I do not know enough to appreciate, Mr. Penney thinks that this movement may actually be from Pennington's workshop. At any rate, he says that neither of the two serial numbers (798 on the back plate, 2021 on the dial) corresponds to either of the two sequences used on Hatton's other products. (I have to add that I have looked at images of a number of signed Pennington movements including Nos. 763 and 765, and none of them matches the shape of the cock or the layout of the set-up shown on my example.) However this may be, it is enough for me to have a working example of Earnshaw's escapement – I have never actually seen, much less owned, one of these before – and to know that it is more than two hundred years old. Note the pillar screws. The balance-spring is of the helical type, with six turns, and is made of gold. The overall diameter is 48mm. I am sorry my images are no better; my hands are not steady enough nowadays, and there is no space in my insanely overcrowded environment to set up a tripod. However, the side view does give a glimpse of the escape-wheel and, to the right of it, the outer end of the detent. The spring of this is a little battered, as I understand is often the case; nonetheless it functions and the movement runs strongly, albeit with a gain of several minutes a day – a fault which I cannot hope to correct, since I am not qualified to meddle with the balance screws. I realise I should perhaps have posted in the Chronometer section; my excuse for not doing so is that I feel a small movement like this, obviously intended for an ordinary (if rather deep) watch-case, could not have been used at sea and is therefore not a true marine chronometer. Besides, to be honest, I was afraid not many people would see it there. Oliver Mundy.