Chronometers should be kept free from damp, dust, and draughts. When winding turn the key steadily, avoiding any jerky action. Most of them require seven and a half turns of the key. Wind slowly and steadily as far as the mechanism will permit. Wind punctually at the same hour every day. A chronometer that has run down, on being wound up again, will probably not start until it has been quickly but not violently slued half round and back again. This is easily done by placing the instrument on the table, and turning it horizontally between the hands. Take care that the instrument has neither too much nor too little side-play in the gimbals. A standard compass stowed away, while in port, close to a chronometer has been known to ruin the going of the watch, the powerful compass needles having by induction magnetized the steel portion of the balance. Do not stow a chronometer close to an iron bulkhead, an iron vessel's side, the upper or lower end of a vertical iron stanchion, or within eight feet of compass compensating magnets. The chronometer case should not be screwed down to a table containing drawers which might possibly be used to hold spare compass cards. Chronometers should be kept away from iron almost as religiously as compasses.
Jolting in a railway train or a conveyance of any description is liable to alter the steady going of a chronom-
