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The Method of Finding the Longitude at Sea, by Time-Keepers: To Which Are ...
No preview available - 2018
The Method of Finding the Longitude at Sea by Time-Keepers: To Which Are ...
No preview available - 2015
24 hours according added alſo altitude angle apparent apparent noon axis becauſe bring called caſe circle column Correction deviation diffe difference divided earth eaſt equal equation exactly EXAMPLE faſt firſt fixed gain give given going greater half half-interval horizon inſtrument interval laſt latitude latter leſs limb logarithm loſs manner mark mean meridian method middle minutes month morning motion muſt Nautical Almanac nearly neceſſary noon noon at Greenwich o's Long object obſervations obtained oppoſite paſſed proper purpoſe quantity remainder right aſcenſion ſame ſcrew ſecond ſet ſhewn ſhip ſigns ſlow ſome ſtar ſubtracted ſuch ſum ſun Sun's ſun's declination ſun's longitude ſuppoſe Table taken teleſcope theſe thoſe time-keeper tion tranſit true tube turn uſe watch weſt whole wire ܕܐ ܕܘ ܘܘ ܕܘ ܘܘ ܕܘ ܘܘ ܘܘ ܕܘ ܘܘܕܘ ܘܘܕܘ ܘܘ ܕܘ
Page 18 - and the time correfponding to it will be the apparent time from the neareft noon: confequently, if the obfervation be made in the morning, the time thus found muft be taken from 24. hours, and the remainder will be the apparent time from the noon of the preceding day.
Page 9 - As the earth revolves uniformly on its axis, if it had no annual motion in its orbit, or if that motion was uniform, and in a plane
Page 29 - a telefcope, of any convenient length, fixed at right angles to an horizontal axis; on which it turns in the plane of the meridian,
Page 18 - latitude, and the logarithmic fecant of the fun's declination ; their fum,' rejecting 20 from the index, muft be fought for in Table XVI. under log-rifing, and the time correfponding to it will be the
Page 21 - it will always Ihew the mean time at the firft meridian. Hence, if the mean time be found at the ihip, by the preceding problem, the difference between it and the time
Page 21 - will continue to ihew the mean time at that meridian, as long as it continues to go at the fame rate, whatever place it may be carried to : and,
Page 56 - attend again to the watch. And in this manner the times when the fun's firft limb arrives at every one of the wires muft be obferved, and noted down in its proper column. The times when the fécond limb arrives at each of the five wires muft be obferved in the fame manner, and written in
Page xv - fhip is no otherwife an impediment in this fort of obfervations, than as it renders the repetition of them more