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The Portable Transit Instrument in the Vertical of the Pole Star: Translated From the Original Memoir of Wm; Döllen (Classic Reprint) - Tapa blanda
Sinopsis
Excerpt from The Portable Transit Instrument in the Vertical of the Pole Star: Translated From the Original Memoir of Wm; Döllen
On the other hand the experienced computer will certainly not fail to make full use of the advantages offered by the smallness of most of the desired quantities, and that, too, without impairing in the least the perfect exactness of the result.
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This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
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Excerpt from The Portable Transit Instrument in the Vertical of the Pole Star: Translated From the Original Memoir of Wm; Döllen
On the other hand the experienced computer will certainly not fail to make full use of the advantages offered by the smallness of most of the desired quantities, and that, too, without impairing in the least the perfect exactness of the result.
About the Publisher
Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com
This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
Reseña del editor
Excerpt from The Portable Transit Instrument in the Vertical of the Pole Star: Translated From the Original Memoir of Wm; Döllen
This will, however, be absolutely necessary, if perhaps, as only too easily happens with the traveler, the mounting is by no means solid enough to sufficiently assure the invariability of the instrument during the entire interval necessary to a complete time determination in the meridian. In fact, under such circumstances no other method remains than to limit the duration of the observations to the shortest possible time, and to effect this, therefore, it is necessary to not wait until the proper stars, especially those situated near the pole and necessary for orientation, have reached the meridian, but to leave the meridian and to seek the most appropriate of them all, Polaris itself, wherever it may be in its diurnal circle. The dexterity of the observer will then show itself in the shortness of the interval which elapses after or even before the transit of Polaris over one of the threads of the reticule and the observation of the transit of the time star proper, (of course on all or at least as many threads as possible;) and we know from much experience that with a little practice this interval need be only a few minutes. The observation in the first position is completed by a careful determination of the inclination of the horizontal axis, or, as is very desirable, by two determinations inclosing the observations of the stars, and whose agreement bears testimony to the actual invariability of the instrument. It is, however, important immediately to execute a similar series of observations in the other position of the instrument, in order to free the result from the influence of the error of collimation and the difference in diameters of the pivots, without being under the necessity of taking these quantities from other sources.
It is easy, and will certainly also be intended in these observations, to observe Polaris both times upon the same thread, by preference the middle thread, and the succeeding computation will, in fact, be thereby somewhat simplified. One easily sees, however, that so far as concerns the true object of the observation, this is quite without serious importance, while in the execution of the observation a great relief may result from not being bound to any such condition. This stands in connection, however, with certain imperfections of the transit instruments in their present construction, to which the attention of the observer deserves to be especially called.
3. The instrument to which the following remarks are especially applicable is the Ertel portable transit instrument, although they certainly have also a more general importance. This instrument, in different forms, but all of nearly identical construction, has attained an extensive distribution, and may, indeed, through the descriptions given in words and drawings in different authorities, be considered as generally known. It differs chiefly from the formerly much-used Troughton's transit in the broken telescope and the possibility of the motion about the vertical axis. The former secures a marked facility in the observation, especially in the neighborhood of the zenith, and by reason of the shortening of the supports of the horizontal axis conduces much to give a greater rigidity to the entire instrument.
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The Portable Transit Instrument in the Vertical of the Pole Star
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Paperback. Condición: New. Print on Demand. This book presents an in-depth investigation into the history and practice of observing time, featuring the portable transit instrument and its application to celestial observations. The author combines theoretical knowledge with practical experience, offering valuable insights for astronomers and historians alike. By utilizing the portable transit instrument, which allows for accurate time determination in various locations, the author explores the method of observing Polaris, the North Star, to establish precise time measurements. This innovative approach not only improves the accuracy of timekeeping but also simplifies the process, making it more accessible to researchers in the field. The book delves into the intricacies of time determination, shedding light on the challenges and advancements associated with this crucial practice. Moreover, it discusses the broader implications of precise timekeeping for navigation, communication, and scientific research, highlighting the significance of this technique in shaping our understanding of the universe and our place within it. This book is a reproduction of an important historical work, digitally reconstructed using state-of-the-art technology to preserve the original format. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in the book. print-on-demand item. Nº de ref. del artículo: 9781332028061_0
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The Portable Transit Instrument in the Vertical of the Pole Star Translated From the Original Memoir of Wm Dllen Classic Reprint
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The Portable Transit Instrument in the Vertical of the Pole Star Translated From the Original Memoir of Wm Dllen Classic Reprint
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