“This fundamental and most important article being established upon such full evidence, it remained to be examined within what limits the errors arising from observations actually taken at sea could be contained.
In order to determine this point, I computed the ship's longitude from each of the observations made by captain Campbell, and, upon comparing the results of several that were taken near the same time and under the like circumstances, it appeared that in general the observer was not liable to err more than one minute in judging of the apparent contact of the moon's limb and the object with which it was compared. Now this being nearly the same error that would be found to obtain, if the like observations were to be made with the same instruments on land, it may hence be inferred, that in moderate weather the motion of the ship is no otherwise an impediment in this sort of observations, than as it renders the repetition of them more tedious and troublesome to the observer, which yet ought by no means to be omitted; because if each single observation be liable to an error of a minute only, by taking the mean of five or six, the error on this head may be so far diminished as to be of small moment.”

Miscellaneous Works and Correspondence (1832), To Mr. Cleveland Secretary of the Admiralty (April 14, 1760)

Adopted from Wikiquote. Last update June 3, 2021. History

Help us to complete the source, original and additional information

Do you have more details about the quote "This fundamental and most important article being established upon such full evidence, it remained to be examined withi…" by James Bradley?

James Bradley11

English astronomer; Astronomer Royal 1693–1762

Related quotes

“Sir,
Having long deferred to make any report relating to the observations that were taken at sea by captain Campbell, in the year 1757, which you transmitted to me by order of the lords of the admiralty, I think it necessary to acquaint you, that, upon examining those observations, I perceived that they were not in all respects accompanied with such circumstances as are requisite for forming a right judgment of the accuracy and certainty with which observations proper for finding the longitude at sea by the moon can in fact be taken; for which reason I delayed giving my opinion upon this point till I could have an opportunity of comparing a greater variety of observations, made at different times, and with different instruments: such an opportunity having lately been given me by captain Campbell, who has favoured me with a copy of several observations that were made by him in 1758 and 1759, I now beg leave to lay before their lordships the result of the comparisons which I have made.”

James Bradley (1693–1762) English astronomer; Astronomer Royal

Miscellaneous Works and Correspondence (1832), To Mr. Cleveland Secretary of the Admiralty (April 14, 1760)

“But before I proceed farther it may be proper to take notice, that since the time when I gave their lordships an account of the near agreement of Mr. Professor Mayer's lunar tables with the observations that had been then made at the Royal Observatory, I have compared several others, which concurred to prove that the difference between the observed and computed places nowhere amounted to more than about one minute and a half; and I find that the difference (small as it is) may yet be diminished by making alterations in some of the equations, whose true quantity could not be determined without proper observations; after making the needful corrections it appeared, by the comparison of above eleven hundred observations taken here since the new instruments were fixed up, that the difference did nowhere amount to more than a minute: it may therefore be reasonably concluded, that so far as it will depend upon the lunar tables the true longitude of a ship at sea may in all cases be found within about half a degree, and generally much nearer.”

James Bradley (1693–1762) English astronomer; Astronomer Royal

Miscellaneous Works and Correspondence (1832), To Mr. Cleveland Secretary of the Admiralty (April 14, 1760)

“I would by no means attempt to infer from hence, that the longitude found by observations of this sort may in all cases be depended upon within one degree; but I beg leave to observe, that whatever extraordinary circumstances may have concurred to produce so near an agreement in this particular case, the event is such as may give reason to hope, however great the difficulties of finding the longitude by this method seem to be, that they are not insuperable, or such as ought to deter those whom it most nearly concerns from attempting to remove them.”

James Bradley (1693–1762) English astronomer; Astronomer Royal

Miscellaneous Works and Correspondence (1832), To Mr. Cleveland Secretary of the Admiralty (April 14, 1760)

“A time series is a sequence of observations, usually ordered in time, although in some cases the ordering may be according to another dimension. The feature of time series analysis which distinguishes it from other statistical analysis is the explicit recognition of the importance of the order in which the observations are made. While in many problems the observations are statistically independent, in time series successive observations may be dependent, and the dependence may depend on the positions in the sequence. The nature of a series and the structure of its generating process also may involve in other ways the sequence in which the observations are taken.”

Theodore Wilbur Anderson (1918–2016) American statistician

T. W. Anderson. The Statistical Analysis of Time Series http://books.google.com/books?hl=nl&lr=&id=rCOzXIC8ZLkC&oi=fnd&pg=PR11, (1971/2011), p. 1. Introduction; Cited in: American Sociological Association (1974), Sociological Methodology, p. 310

“The activity of observing establishes a distinction in a space that remains unmarked, the space from which the observer executes the distinction. The observer must employ a distinction in order to generate the difference between unmarked and marked space, and between himself and what he indicates. The whole point of this distinction (its intention) is to mark something as distinct from something else. At the same time, the observer — in drawing a distinction - makes himself visable to others. He betrays his presence - even if a further distinction is required to distinguish him.”

Niklas Luhmann (1927–1998) German sociologist, administration expert, and social systems theorist

Source: Art As a Social System (2000), p. 54 as cited in: Pamela M. Lee (2004) Chronophobia: On Time in the Art of the 1960's. p. 66.

“The range of H 1255 is only four tenths of a magnitude, and on account of its brightness it is difficult to observe on all plates except those taken with the 1-inch Cooke lens. It seemed necessary, therefore, to take unusual precautions in order to secure accurate observations, and to give each one its full weight. Accordingly, one hundred and thirty six photographs were selected, including nearly all of those taken with the Cooke lens, and also those taken with the 8 inch Bache Telescope on which the variable was certainly faint. Four independent estimates of brightness were made on each plate, and means were taken, thus reducing the probable error one half. The phase was computed for each observation, thus covering all parts of the light curve. …H 1255 and H 1303 differ from the other variables in a marked degree as in each case the duration of the phase of minimum is very long in proportion to the length of the period. This fact led to considerable difficulty in determining their periods as they were apparently at their minimum brightness for some time before and after the actual minima occurred. In H 1255, the change in brightness is obviously continuous throughout the period, although it is much more rapid near minimum than near maximum. This is clearly seen in Plate IV, Figs. 5 and 6.”

Henrietta Swan Leavitt (1868–1921) astronomer

"Ten Variable Stars of the Algol Type" http://books.google.com/books?id=UkdWAAAAYAAJ&pg=PA87 (1908) Annals of the Astronomical Observatory of Harvard College Vol.60. No.5

“War taken at the best is a frightful scourge to the human race; but because it is so the wisdom of ages has surrounded it with strict laws and usages, and has required formalities to be observed which shall act as a curb upon the wild passions of man, to prevent that scourge from being let loose unless under circumstances of full deliberation and from absolute necessity. You have dispensed with all these precautions.”

William Ewart Gladstone (1809–1898) British Liberal politician and prime minister of the United Kingdom

Speech https://api.parliament.uk/historic-hansard/commons/1857/mar/03/resolution-moved-resumed-debate-fourth#column_1802 in the House of Commons against the Second Opium War (3 March 1857) <br class="br">1850s

“The functional validity of a working hypothesis is not a priori certain, because often it is initially based on intuition. However, logical deductions from such a hypothesis provide expectations (so called prognoses) as to the circumstances under which certain phenomena will appear in nature. Such a postulate or working hypothesis can then be substantiated by additional observations or by experiments especially arranged to test details. The value of the hypothesis is strengthened if the observed facts fit the expectation within the limits of permissible error.”

Reinout Willem van Bemmelen (1904–1983) Dutch geologist

Source: "The Scientific Character of Geology," 1961, p. 454; As cited in: Alberta Research Council, ‎Research Council of Alberta (1964), Bulletin - Alberta Research Council. Vol. 15-17, p. 31

“You will observe, I think, that repentance is seldom whole-hearted, and generally arises from such base and ignoble motives as feeling sorry for yourself in dire circumstances.”

Lin Carter book Kesrick

Source: Kesrick (1982), Chapter 23, “Gaglioffo Repents” (p. 147)

“There is no direct observational evidence for the curvature [of space], the only directly observed data being the mean density and the expansion, which latter proves that the actual universe corresponds to the non-statical case. It is therefore clear that from the direct data of observation we can derive neither the sign nor that value of the curvature, and the question arises whether it is possible to represent the observed facts without introducing the curvature at all. Historically the term containing the 'cosmological constant λ' was introduced into the field equations in order to enable us to account theoretically for the existence of a finite mean density in a static universe. It now appears that in the dynamical case this end can be reached without the introduction of λ.”

Willem de Sitter (1872–1934) Dutch cosmologist

Joint memoir with Einstein (1932) as quoted by Gerald James Whitrow, The Structure of the Universe: An Introduction to Cosmology (1949)

Help us to complete the source, original and additional information

James Bradley11

Related quotes

Related topics