Xlii AN ACCOUNT OF THE 



of rising and setting of the sun, moon, and stars j 

 and the positions of the stars for any time of the 

 night. 



In the ye#r 1747, I published a Dissertation on 

 the Phenomena of the Harvest Moon, with the de- 

 scription of a new Orrery, in which there were only 

 four wheels. But having never had a grammatical 

 education, nor time to study the rules of just com- 

 position, I acknowledge that I was afraid to put 

 it to press; aod, for the same cause, I ought 

 to have the same fears still. But having the 

 pleasure to find that this, my first work, was not ill 

 received, I was emboldened to go on, in publish- 

 ing my Astronomy, Mechanical Lectures, Tables 

 and Tracts relative to several Arts and Sciences, 

 The Young Gentleman and Lady's Astronomy, a 

 small treatise on Electricity, and the following 

 sheets. 



In the year 1748, I ventured to read Lectures 

 on the Eclipse of the Sun that fell on the 14th of 

 July in that year. Afterwards I began to read 

 Astronomical Lectures on an Orrery which I made, 

 and of which the figures of all the wheel-work are 

 contained in the 6th and 7th Plates of this book.* 

 I next began to make an apparatus for Lectures on 

 Mechanics, and gradually increased the apparatus 

 for other parts of experimental philosophy, buying 

 from others what I could not make for myself, till 

 I brought it to its present state. I then entirely 



* Mechanical Exercises, 8vo. 



