## Memoir on a New and Certain Method of Ascertaining the Figure of the Earth by Means of Occultations of the Fixed StarsR. and A. Taylor, 1819 - 44 pages |

### From inside the book

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**moon's disc**opposite to the ob- M L server ; C the moon's centre ; and that the radius CV , which divides the arc AVB into two equal parts , coincides with the vertical circle of the place of the observer . Let us further suppose that ... Page 16

... moon at the height of 10 ' is 8 ′′ , 5 : but , if the moon were at the height of 20 ° above the horizon , the variation would be 8 " , 1 ; and at 30 ° it would be 7 " , 4 . B. The smaller the chord of the

... moon at the height of 10 ' is 8 ′′ , 5 : but , if the moon were at the height of 20 ° above the horizon , the variation would be 8 " , 1 ; and at 30 ° it would be 7 " , 4 . B. The smaller the chord of the

**lunar disc**( or the smaller the ... Page 17

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**disc**, provided the earth were a perfect sphere : together with the corresponding durations provided the earth were an oblate spheroid , having the axis compressed . Latitude of the place 60 " : height of the**moon**10 ° . Earth = Sphere ... Page 24

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**moon's disc**; together with a good clock , or watch , beating seconds . And although it would be de- sirable , in all observations of this kind , to have the exact mean time of the immersion and emersion of the star , yet , as it is the ... Page 25

... moon . For the star passes behind so small a seg- ment of the

... moon . For the star passes behind so small a seg- ment of the

**moon's disc**, that it may undergo a partial occultation by the projecting mountains of the moon , before it is wholly hid by that body ; as appears from the following ...### Other editions - View all

Memoir on a New and Certain Method of Ascertaining the Figure of the Earth ... Antonio Cagnoli,Francis Baily No preview available - 2009 |

Memoir on a New and Certain Method of Ascertaining the Figure of the Earth ... M. (Antonio) Cagnoli No preview available - 2012 |

### Common terms and phrases

accurate advantage alluded Année apparent path appears arise Ascension and Declination astro astronomers Astronomical Society Barcelona Board of Longitude Cagnoli calculations chord circumstances compared Connaissance des Tems consequently cultations D's disc dark limb deduce determining the true different latitudes dura duration earth earth's axis earth's radius earth's surface effect emer ences Ephemerides errors Evaux feet FIXED STARS FRANCIS BAILY hitherto hypotheses Ibid illuminated side immersion and emersion labours Latitude 70 length line MV longitude Maupertuis meridian Messier METHOD OF ASCERTAINING mode moon's disc moon's parallax nomy object oblate spheroid observations occultation of Aldebaran parallax of height perfect sphere perpendicular phænomenon Pingré plumb-line polar axis poles precise quantity present produce a difference proposed public attention purpose recent measurement rendered Right Ascension scientific semidiameter sion spect star's passing sufficient supposition telescope terrestrial radii tion true figure variation of curvature vation vertical circle Zodiacal stars

### Popular passages

Page 1 - D'Alembert, was the Precession of the equinoxes and the Nutation of the earth's axis, according to the theory of gravitation.

Page 33 - Pounds in any one Year, towards the making, correcting, or publishing any such Experiments, Modes, Observations, Calculations, or Tables. VII. And whereas it is expedient that the said Commissioners should be enabled to cause to be ascertained, as accurately as may be, the Latitude and Longitude of Places whereof the exact Situation hath not been already sufficiently ascertained ; Be it enacted. That they may expend or cause to be expended any Sum not exceeding in the whole One Thousand Pounds in...

Page 20 - ... that yearly happen, may be readily shown. Indeed, most of the lunar occultations, where the star is of sufficient magnitude for observing its immersion and emersion correctly, are equally fit for the purpose here proposed to some parts or other of the globe. And as Cagnoli very justly observes : — " It is in the power of every principal academy materially to assist in such a discovery, by two methods. First, in regard to times past, to collect together, from all quarters, the observations of...

Page 33 - ... said Commissioners should be enabled to expend certain Sums towards making Experiments of Instruments, Modes, or Proposals, and for making and publishing Observations, Calculations, and Tables for ascertaining the Longitude, or towards improving or correcting such as may have been already made, or for other Purposes useful to Navigation; Be it enacted, That they may pay or expend any Sum or Sums of Money, not exceeding One...

Page 21 - Secondly, w ith respect to the future, to insert in the ephemerides accurate ill notices of. those placee or districts where it would be most important that any occultation should be observed (particularly of the principal stars) in order that it might serve to apprise and excite the attention of such astronomers as might be favourably situated themselves, or contiguous to more advantageous situations.

Page 1 - Memoir on a New and Certain Method of Ascertaining the Figure of the Earth by means of Occultations of the Fixed Stars.

Page 33 - ... Observations, Calculations, or Tables. VII. And whereas it is expedient that the said Commissioners should be enabled to cause to be ascertained, as accurately as may be, the Latitude and Longitude of Places whereof the exact Situation hath not been already sufficiently ascertained ; Be it enacted. That they may expend or cause to be expended any Sum not exceeding in the whole One Thousand Pounds in any one Year for such Purpose. VIII. And whereas it may happen that Proposals, Inventions, and...

Page 33 - ... publishing Observations, Calculations, and Tables for ascertaining the Longitude, or towards improving or correcting such as may have been already made, or for other Purposes useful to Navigation; Be it enacted, That they may pay or expend any Sum or Sums of Money, not exceeding One Thousand Pounds in any one Year, towards the making, correcting, or publishing any such Experiments, Modes, Observations, Calculations, or Tables.

Page 34 - ... moderate Rewards upon the Person or Persons who may have made such Proposal, Invention, or Correction ; Be it therefore enacted, That the said Commissioners may pay or cause to be paid such Sum not exceeding...

Page 8 - ... if there be no variation in the curvature of the earth's surface, the duration will be only 8m.