The Theory and Practice of Finding the Longitude at Sea Or Land: To which are Added, Various Methods of Determining the Latitude of a Place, and Variation of the Compass; with New Tables, Τόμος 1sold, 1809 - 8 σελίδες |
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Σελίδα vii
... period , to offer some opinions on the mechanical construction of ships , an ancient art , but perhaps less improved by long experience than any which we now cultivate with so much success . It is well known , that , although the course ...
... period , to offer some opinions on the mechanical construction of ships , an ancient art , but perhaps less improved by long experience than any which we now cultivate with so much success . It is well known , that , although the course ...
Σελίδα 2
... periods . The first who attempted this circumnavigation was Ferdinand Magellan , a Portuguese . He sailed from Seville , in Spain , August 10 , 1519 , in the ship called the Victory , accompanied by four other vessels . In April 1521 ...
... periods . The first who attempted this circumnavigation was Ferdinand Magellan , a Portuguese . He sailed from Seville , in Spain , August 10 , 1519 , in the ship called the Victory , accompanied by four other vessels . In April 1521 ...
Σελίδα 11
... period of the seasons is completed , and this period is called a Solar Year . The signs Aries , Taurus , Gemini , Cancer , Leo , and Virgo , are called Northern Signs , because they are contained in that part of the Ecliptic which is ...
... period of the seasons is completed , and this period is called a Solar Year . The signs Aries , Taurus , Gemini , Cancer , Leo , and Virgo , are called Northern Signs , because they are contained in that part of the Ecliptic which is ...
Σελίδα 13
... period or portion of time , in which a revolution of the earth , with respect to some point in the heavens , is completed . As the equinoctial points and the line of the apsides have a slow motion , with respect to the fixed stars ...
... period or portion of time , in which a revolution of the earth , with respect to some point in the heavens , is completed . As the equinoctial points and the line of the apsides have a slow motion , with respect to the fixed stars ...
Σελίδα 14
... period there are 692864d . 10h . 32 ' , which being divided by 1897 years , gives 365d . 5h , 48 ′ 46 ′′ nearly , the length of the Tropical Year . Again , M. Cassini , at Bologna , upon the 28th March , 1657 , at Oh . 5 ′ 1 ′′ mean ...
... period there are 692864d . 10h . 32 ' , which being divided by 1897 years , gives 365d . 5h , 48 ′ 46 ′′ nearly , the length of the Tropical Year . Again , M. Cassini , at Bologna , upon the 28th March , 1657 , at Oh . 5 ′ 1 ′′ mean ...
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The Theory and Practice of Finding the Longitude at Sea Or Land: To Which ... Andrew MacKay Δεν υπάρχει διαθέσιμη προεπισκόπηση - 2018 |
The Theory and Practice of Finding the Longitude at Sea Or Land: To Which ... Andrew MacKay Δεν υπάρχει διαθέσιμη προεπισκόπηση - 2023 |
The Theory and Practice of Finding the Longitude at Sea Or Land: To Which ... Andrew MacKay Δεν υπάρχει διαθέσιμη προεπισκόπηση - 2015 |
Συχνά εμφανιζόμενοι όροι και φράσεις
add the log Aldebaran angle apparent altitude apparent distance arch second arch third azimuth Board of Longitude co-s co-secant co-sine co-tangent coloured glass compass computed constant log deduced degree Diff difference of longitude dist Earth eclipse emersion equal altitudes equation error EXAMPLE finding the longitude fixed star given Greenwich hence horizon glass hour angle instrument interval logarithm longitude at sea lunar lunar eclipse magnitude mean meridian altitude meridian distance method of finding Moon Moon's altitude Moon's horizontal parallax motion natural number natural versed sine Nautical Almanac nonagesimal noon object observed altitude orbit parallax in latitude place of observation planet polar distance PROBLEM prop quadrant radius Reduced latitude refraction remainder Required the true Royal Observatory RULE satellites secant semid sextant ship ship's subtracted Sun and Moon Sun's right ascension Table tangent telescope time-keeper true altitude true distance true longitude variation watch zenith distance
Δημοφιλή αποσπάσματα
Σελίδα 36 - ... space is much more rapid than what has now been stated ; or while she accompanies the earth in its motion round the sun, which is at the rate of 68,000 miles an hour, she also moves thirteen times round the earth during the same period, which is equal to a course of nearly twenty millions of miles. The moon's orbit is inclined to the ecliptic in an angle of 5° 9...
Σελίδα 4 - AY and night arise from the circ uoarotatiou of the Earth. That imaginary line about which the rotation is performed, is called the Axis, and its extremeties are called Poles. That towards the most remote parts of 'Europe is called the North Pole, and its opposite the South Pole. The Earth's Axis being produced will point out the Celestial Poles. The Equator is a great circle on the Earth* every point of which is equally distant from the Poles ; it divides the Earth into two equal parts, called...
Σελίδα 19 - This way of considering the sun is of the utmost importance in its consequences. That stars are suns can hardly admit of a doubt. Their immense distance would perfectly exclude them from our view, if the light they send us were not of the solar kind.
Σελίδα 270 - That Mr Harrison's watch cannot be depended upon to keep the longitude within a degree in a West India voyage of six weeks ; nor to keep the longitude within half a degree for more than a fortnight ; and then it must be kept in a place where the thermometer is always some degrees above freezing...
Σελίδα 41 - ... produced very sensible effects, and the motion of the Comet would have suffered the greatest disturbance. In such case the plane and species of its Ellipsis and its periodic Time would have been very much changed, especially from meeting with Jupiter. In the late descent, the true path of this Comet left the Orbits of Saturn and Jupiter below itself a little towards the South : It approached much nearer to the paths of Venus and Mercury, and much nearer still to that of Mars. But as it was passing...
Σελίδα 43 - Newton, we must not omit to state, that the germ of it, and something more, had been previously published by Hooke. In giving an account of the inventions of members of the Royal Society, Sprot mentions " a new instrument for taking angles by reflexion, by which means the eye at the same time sees the two objects both as touching on the same point, though distant almost to a semicircle, which is of great use in promoting exact observations at...
Σελίδα 19 - It appears to me now, that we cannot refuse to admit such a motion, and that indeed it may be as evidently proved as the diurnal motion of the earth. Dark spots, or large portions of the surface less luminous than the rest, turned alternately in certain directions either towards or from us, will account for all the phenomena of periodical changes in the lustre of the stars so satisfactorily, that we certainly need not look out for any other cause.
Σελίδα 19 - A star of the eighth magnitude, with a faint luminous atmosphere of a circular form, and of about 3' in diameter. The star is perfectly in the centre, and the atmosphere is so diluted, faint and equal throughout, that there can be no surmise of its consisting of stars, nor can there be a doubt of the evident connexion between the atmosphere and the star.
Σελίδα 92 - Commons came to the following resolution : " /.. -.,/.,.'. That it is the opinion of this...
Σελίδα 19 - On our sun these spots are changeable. So they are on the star o Ceti; as evidently appears from the irregularity of its changeable lustre, which is often broken in upon by accidental changes, while the general period continues unaltered. The same little deviations have been observed in other periodical stars , and ought to be ascribed to the same cause.