Burney del.

London, Publishd Oct.10.1788, by Geo. Adams, N° 60 Fleet Street.

Laurie fe.

AND

GEOGRAPHICAL

ESSAYS:

CONTAINING,

I.

A COMPREHENSIVE VIEW OF THE

General Principles of Aftronomy.

CELESTIAL AND TERRESTRIAL GLOBES,

Exemplified in a Variety of PROBLEMS, which are defigned to illuftrate
the Phænomena of the Earth and Heavens, in the most

eafy and natural Manner.

III.

THE DESCRIPTION AND USE OF THE

ARMILLARY SPHERE, PLANETARIUM,
TELLURIAN, AND LUNARIUM.

PRACTICAL ASTRONOMY;
Or, the USE of the QUADRANT and EQUATORIAL,

By GEORGE ADAMS,

MATHEMATICAL - INSTRUMENT MAKER TO HIS MAJESTY, AND OPTICIAN TO HIS
ROYAL HIGHNESS THE PRINCE OF WALES.

LONDON:

Printed for the AUTHOR, by R. HINDMARSH, Printer to His
Royal Highness the Prince of Wales, No. 32, Clerkenwell- Clofe;
and Sold at the Author's Shop, No. 60, Fleet-Street,

M.DCC.LXXXIX,

1

PREFACE,

THE

HE connection of aftronomy with geography is fo evident, and both in conjunction fo neceffary to a liberal education, that no man will be thought to have deserved ill of the republic of letters, who has applied his endeavours to diffufe more univerfally the knowledge of these useful fciences, or to render the attainment of them easier; for as no branch of literature can be fully comprehended without them, fo there is none which impress more pleafing ideas on the mind, or that afford it a more rational entertainment.

The fifth edition of my father's treatise on the globes being out of print, I was folicited to reprint it. To obviate feveral objections to the

form

form in which he had difpofed the problems, I was induced to undertake the present work, in which they are arranged in a more methodical manner, and a great number added to them. Such facts are also occafionally introduced, and fuch obfervations interfperfed, as it is prefumed will excite curiofity, and fix attention.

Having proceeded fo far in this work, I found that it was easy to render it subservient to my plan of publishing, from time to time, "ESSAYS, DESCRIBING THE USE OF MATHE MATICAL AND PHILOSOPHICAL INSTRUMENTS:" for the defcription of those which have been contrived to smooth the path to the science of astronomy, could no where be introduced with fo much propriety, as in a work which treated of it's elementary principles,

To further this defign, it was necessary to prefix an introduction to aftronomy. This is divided into three parts. In the first, the pupil is fuppofed to be placed in the fun, the center of the folar system; from this fituation he confiders the motion of the heavenly hoft, and finds that all is regular and harmonious. In the fecond part, his attention is directed to the appearances of the planetary bodies, as obferved from the

earth.