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. By Andrew Mackay, ...J. Sewell, P. Elmsly, and J. Evans, 1793 |
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Αποτελέσματα 1 - 5 από τα 14.
Σελίδα 25
... instrument , and broader towards the axis of motion ; at the other end of the index , a piece of brafs turns up , behind the limb , having a spring to make the dividing fcale lie close to the limb , and a fcrew to faften it in any ...
... instrument , and broader towards the axis of motion ; at the other end of the index , a piece of brafs turns up , behind the limb , having a spring to make the dividing fcale lie close to the limb , and a fcrew to faften it in any ...
Σελίδα 41
... instrument in a horizontal pofition ; then direct the fight to the horizon glafs , and if the reflected horizon is apparently in the fame ftraight line with that feen directly , the glass is perpendicular to the plane of the fextant ...
... instrument in a horizontal pofition ; then direct the fight to the horizon glafs , and if the reflected horizon is apparently in the fame ftraight line with that feen directly , the glass is perpendicular to the plane of the fextant ...
Σελίδα 42
... instrument , and let two diftant objects be felected , as two ftars of the first magni- tude , or the Sun and Moon , whofe distance may not be less than 90 ° or 100 ° ; make the contact of the limbs of these objects as per- fect as ...
... instrument , and let two diftant objects be felected , as two ftars of the first magni- tude , or the Sun and Moon , whofe distance may not be less than 90 ° or 100 ° ; make the contact of the limbs of these objects as per- fect as ...
Σελίδα 43
... instrument , and if the Sun is very bright , raife the plate be- fore the filvered part of the fpeculum ; direct the telescope either to the tranfparent part of the horizon glafs , or to the line which fepa- rates the filvered and ...
... instrument , and if the Sun is very bright , raife the plate be- fore the filvered part of the fpeculum ; direct the telescope either to the tranfparent part of the horizon glafs , or to the line which fepa- rates the filvered and ...
Σελίδα 44
... INSTRUMENT OF REFLECTION . TH HIS inftrument was propofed , with a view to correct the er- rors to which a fextant is liable , and in particular the error arifing from the inaccuracy of the divifions on the limb . It was in- vented by ...
... INSTRUMENT OF REFLECTION . TH HIS inftrument was propofed , with a view to correct the er- rors to which a fextant is liable , and in particular the error arifing from the inaccuracy of the divifions on the limb . It was in- vented by ...
Άλλες εκδόσεις - Προβολή όλων
The Theory And Practice Of Finding The Longitude At Sea Or Land Andrew MacKay Δεν υπάρχει διαθέσιμη προεπισκόπηση - 2018 |
The Theory and Practice of Finding the Longitude at Sea Or Land Andrew MacKay Δεν υπάρχει διαθέσιμη προεπισκόπηση - 2015 |
Συχνά εμφανιζόμενοι όροι και φράσεις
Aberdeen add the log adjuſtment alfo alſo anfwering angle apparent altitude apparent diſtance arc fecond arc firft arch Arcturus arifing azimuth becauſe cafe co-fecant co-fine co-tangent Co-verfed computing correction correfponding courſe degrees Diff dift divifion Earth ecliptic emerfion equal altitudes equation error fame fecant feen femidiameter fextant fhip fhould figns fince finding the Longitude firſt Fixed Star folar ftar fubtract given glaſs greateſt Greenwich half Hence horizon glafs horizontal parallax increaſe inftrument interfection interval laſt latitude lefs limb logarithm mean meaſured meridian method Moon moſt motion muſt Nautical Almanac neareſt neceffary nonagefimal noon obferved altitude object Obliq paffing place of obfervation planet pofition purpoſe quadrant reduced Reduced latitude refraction Rifing ſhip ſtar Sun's right afcenfion tangent teleſcope thefe theſe tion tranfit true altitude true diſtance true longitude tude uſed variation Verfed Verfed fine watch weft zenith diſtance ΙΟ