The USE of the Universal Ring-Dial.  

To find the hour of the Day.  
SEt the Stroke in the Sliding Piece, to the Latitude of the Place, and set the Stroke crossing the little hole in the Bridge or Middle Piece, to the Day of the Month; then open the Rings, and hold them up by the Little Ring, and move the Bridge, or Middle Piece, so towards the Sun, according as you may think to be near the Hour, and move it gently this way and that, till the Sun shining thorough the little hole in the Bridge, you can discern a little Ray or Speck of Light, to fall upon the Aequinoctial, within side, among the Hours; and the Point in the Middle Line, whereon the Ray or Speck falleth, is the True Hour of the Day.   

To find the Altitude of the Sun.  
Set the Stroke in the Sliding Piece, to the beginning of Degrees, and put a Pin thorough the Hole on the Backside of the Ring, and the Shadow of the Pin shall show the Altitude on the Large Quadrant on the Backside.   

To find the Sun's Declination.  
Set the Stroke crossing the little hole in the Bridge, to the Day of the Month, and against it, on the other side, is the Sun's Declination.   

To find the Latitude of the Place.  
First find the Sun's Meridian, or greatest Altitude for that Day observed; then find the Sun's Declination for that Day. If that you make your Observation in the Summer Half Year, viz. from the 10th of March to the 12th of September, than you must subtract the Declination from the Altitude; but if you observe in the Winter Half Year, viz. from the 12th of September to the 10th of March, than you must add the Declination of the Altitude, and either of those Numbers is the Height of the Aequinoctial, which subtract from 90 degrees, is the Latitude of the Place.    

This Instrument, or any other useful for the Mathematics, are Made and Sold by Tho. Walpoole at the Sign of the Mariner and Compass in the Minories 1696.