Morning journal and courier., 1885-07-25
CHRONOMETERS.
An old Salt Water Sailor Chats About
 Them.

[Chicago Herald Interview.]
 ''I noticed the other day,' remarked an old salt water sailor, who now lives on Kos suth street, "that you had something in the paper about chronometers. Now, I happen to have had some experience in the use of chronometers. People see them in the jew eler's window, compare their watches and pass. Few stop to think of the relations they hold to life and property on the ocean, Time was when ships were guided to differ ent parts of the world without them, but at frightful sacrifice of time, and often of ship, cargo and crew. Then the only means they had of determining their longitude was by dead reckoning, and that was very poor thing to depend on. The old way was to get into the latitude of the port sailed for and then steer east or west as the case demanded But the chronometer has done away with all that. Now a captain can leave a port and shape hls course to any part of the globe, and know his true position, in clear weather, every day There are two gentlemen in this city whose fathers sailed from the shores of Massachusetts bay, around Cape Horn and Cape of Good Hope without chronometers, but there very few that would undertake it now. Some captains own their chronome- ters, some hire them, others belong to the ship. Some carry two, and if the captain carries his wife with him she has good cause to be jealous of the care and attention that her husband gives to the chronometer She is only second in his thought on shipboard. [ have known captain to take the pillow from under his wife's head to set the chro- uometer on during heavy sea. have of ten taken the chronometer out of it's outer box and set it on pillows, when we were handling heavy cargo, to save it from any sudden jar. All captains have certain time to wind their ehronometers, generally at eight-bells in the morning. The captain wife, as general thing, dare not look at it, and she feels toward it accordingly But there exceptions to this rule There are some captains wives that are first-class navi- gators. For instance, some years ago the .sfner1can ship Ne Plus Ultra left Liverpool for Bombay, Captain Hummer. He had his wife and family with him. After few days he was taken with paralytic shock. His wife napigated the ship successfully to her destination, buried two children on the pas sage and lost her husband three days after reaching port She and her only boy came home in the ship that was in. She looked fully as noble as she had proved herself to be.
 ''Sailors have to be very careful with their chronometers. A brass plate fits over the Aeyhole and works with string, so that as soon as the key is removed it covers the hole
 
 ply get into the works. Every chronometer carries her record with her. The cover forms almost half of the box in which she sets In that cover is where the rates are kept from the time that she left the makers hands. If she is good chronometer you will find all her rates there. After each voy- age she IS taken to chronometer-maker and and rerated, and they often run for years on the same rate. Now, if chronometer gains one-tenth of a second to-day and loses one tenth tomorrow, which is & very small item, she is no use for the purpose for which she was intended, but she would be just the thing for jewellers window. But if, on the other hand, she gained two hours every twenty four hours, or lost the same, and kept doing so, then you have frst-class chronometer This seems strange, but in the first case you could not keep track of her and in the sec- ond case you could. No matter what she gains or loses as long as she keeps on doing the same thing she is all that you want Some will say, Why are they so particular about time at seaa But when it is taken into consideration what proportion second is to a mile it will be plainly seen why we have to be so particular. There are fifteen degrees to the hour, four minutes to the degree, if teen miles to minute, and four seconds to the mile, so that error of one second is one fourth of mile.
 1.-The trouble with chronometers is that they are so affected by the temperature. The slower the movement and the colder it is the faster she runs. We tell the longitude by the chroncmeter. This is set to Green wich time and the calculations are based on the principle that for every degree of lougi- tude east of Greenwich local time will be four minutes faster, and for every degree west four minutes slower. The best chro- nometers will run with surprising accuracy in all temperatures, but they are not perfect, and as the slightest variation means much to the navigator, he has his instrument tested frequently and the rate ascertaned. The rate is the variation of the instrument with temperature, and by observing temperature the captain keeps a record of the variations of his chronometer, and thus corrects the time as indicated by the instrument.
 In testing chronometers they are subject to turn to different degrees of temperature and their variation scientifically observed, is registered inside the cover there. Every good chronometer will go accurately at two temperatures, and can be adjusted to any given temperature. For instance, one in- strument may be made to go accurately in temperature of forty, and also in tempera- ture of eighty, at other temperatures being not so accurate. By constantly endeavoring to keep his chronometel in its best tempera- ture the captain is usually able to rely conf dently upon it's accuracy, though many wrecks have been caused by over-confdence in chronometers.