Shelfmark

dvi.1

Maker

Davis

Subjects

Navigation (sun chronometer tables); Astronomy

Title

Davis’s “Chronometer” Tables

Description

Tables giving hour angles which represent local apparent time for exact degrees of altitude, latitude and declination of the sun.
The hour angle must be corrected for the effect of neglected mintutes in every hour in order to obtain an accurate apparent time.

Document contains:
- Preface: notes previous attempts to create such a table by M. Hommey in 1863, Jerome Lalande in 1793, and Thomas Lynn in 1827. Also notes that the method loses its accuracy in higher latitudes, and that the table is not intended to solve spherical triangles but to provide a quick and easy way of finding longitude at sea with sufficient accuracy for practical purposes.
- Explanation and use: explains how to use the tables and correct them for neglected minutes. An example of a calculation is given.
- Tables for all latitudes.

Earliest Date

Latest Date

Pages

206

Address

London

Other Makers

Printed by Neill and Co. Ltd. Edinburgh.

Cat no

Contents List

Hardback

Prices

Index

Illustrations

General Ref