A N

INTRODUCTION

TO THE

USE of the GLOBES,

AND THE

ORRER Y:

With the Application of
ASTRONOMY to CHRONOLOGY.

Adapted to the

INSTRUCTION and ENTERTAINMENT
of fuch Perfons as are not previously
verfed in Mathematic Science.

WITH AN

APPEN D. I X,
Attempting to explain the Account of the
First and Fourth Days Work of CREA-
TION in the First Chapter of Genefis.

By DAVID JENNINGS.

LONDON:

Printed for J. NOURSE, at the Lamb, facing:
Catherine-Street in the Strand; J. OSWALD,
at the Rofe and Crown in the Poultry, near the
Manfion-Houfe; and J. BUCKLAND, at the Buck
in Pater-nofter Row, near St. Paul's.

M DCC XLVII.

364.358-8. Kor

THE

PREFACE.

HE Perfons for whofe Sake

T

and Ufe the following Treatife was at first drawn up, (or rather, I fhould fay, as to the bigger Part of it, this Collection was made out of many other and bigger Books) are chiefly fuch, who, tho' they have not the Opportunity of attending to the more abftrufe Parts of Mathematic Science, are defirous of, at least, fome general Knowledge of these Matters; fuch who, tho' Providence has marked out their Track of Life thro' Scenes of worldly Bufinefs, yet have Souls large enough to extend themselves, now and then, beyond this little Planet, and to take a distant View of other remote Worlds; in the Contemplation of which, both the philofophic and pious Mind may find its Account, for Entertainment and Profit. The Works of A 2 the

the Lord are great, fought out of all them that have Pleasure therein.

I have endeavoured to keep my Readers of this fort every where in View; and I hope nothing will be found here which is above their Reach; except, perhaps, in the Ninth and Tenth Chapters of the Second Part; where, indeed, the Reader is fuppofed to have a little previous Knowledge of the Doctrine of Angels: But that is fo little, and may be fo presently attained, that it need hardly be mentioned as an Exception to my general Design, of writing for the Inftruction of the Unlearned.

The Method in which I have handled the Doctrine and Ufe of the Globes, in the first Part, is fomewhat fingular. For moft, if not all other Writers on that Subject, have treated on both Globes, as preparatory even to learning Geography; whereby, methinks, they have made the Threshold to that Science, a great deal higher than it need be. I fee no Occafion to perplex a young Mind with Right and Oblique Afcenfion, and Defcenfion, and Afcenfional Difference, and many other puzzling Matters, which have no Relation to Geography, before he can be led into an Acquaintance with Lands and Seas, and Kingdoms and Provinces. I have, therefore, in the firft Place, explained the Terrestrial Globe only, as if there were no fuch

Thing as a Celestial one; after which I would propofe that the young Student fhould read fome Syftem of Geography, before he proceeds to the Celestial Globe.

For the Ufe of the Globes I have given only Twenty Problems, out of a Multitude that may be found in almost any Book on that Subject: But I conceive these Twenty are fo far fufficient, that if a Perfon is Master of them, he will be able readily to work any that he meets with in other Books. The best Collection of this Sort, that I know of, is in Dr. Watts's Knowledge of the Heavens and Earth made eafy; to which, therefore, I would refer the Learner, for his further Practice and Entertainment.

A good deal of the Second Part is adapted to the Ufe of the Orrery, for which Purpose it was drawn up; and, perhaps, an Inftrument of that Sort may be needful to illustrate some of the Chapters, and to render them easily intelligible, to fuch Perfons whose Instruction is here chiefly aimed at. However I would propofe the following cheap and eafy Contrivances to those who are not furnished with that noble Inftrument; which may serve tolerably well instead of it.

To help the Imagination to conceive of the double Motion of the Earth, viz. its annual Motion round the Sun, and its di

urnal