Mr. Huddart’s Observations 
3 ® 
the contrary; which laminae being taken at infinitely small 
distances, the ray of light will form a curve, agreeable to the 
laws of dioptrics. 
In order to establish this principle in horizontal refractions, 
I traced over various parts of this shore at different times, when 
those appearances seemed favourable, with a good telescope, 
and found objects sufficient to confirm it ; though it be difficult 
at that distance of the land to get terrestrial objects well defined 
so near the horizon, as will afterwards appear. 
One day observing the land elevated, and seeing a small 
vessel at about eight miles distance, I from my window di- 
rected my telescope to her, and thought her a fitter object than 
any other I had seen for the purpose of explaining the phseno- 
mena of these refractions. The telescope was forty feet above 
the level of the sea. The boat's mast about thirty-five feet, she 
being about twenty to thirty tons burthen. The barometer at 
29,7 inches, and Fahrenheit’s thermometer at 54 0 . 
The appearance of the vessel, as magnified in the telescope, 
was as represented in fig. 3, and from the mast head to the 
boom was well defined. I pretty distinctly saw the head and 
shoulders of the man at the helm ; but the hull of the vessel 
was contracted, confused, and ill defined : the inverted image 
began to be well defined at the boom (for I could not clearly 
perceive the man -at the helm inverted), and from the boom to 
the horizon of the sea the sails were well defined, and I could 
see a small opening above the horizon of the sea, in the angle 
made by the gaff and mast; and had the mast been shorter by 
ten feet (to the height of y), the whole would have been ele- 
vated above the horizon of the sea, and from y to d an open 
space. This drawing was taken from a sketch I took at the 
