592 
( 
Proceedings of the Royal Society 
air’s density must, according to the narrative, have subsisted 
for hours over the whole sea-reach of Ramsgate, yet, in the course 
of his observations, the Professor himself went to the height of 
80 feet, and has not recorded anything remarkable in the state of 
the air there. Nor is this all ; the ships came and went ; there 
must have been a fresh breeze blowing, notwithstanding of which 
this wonderful, this inconceivable condition of the atmosphere 
continued. 
Though at such a great distance, the minute details of the upper 
rigging are visible. Not only must the telescope have had extra- 
ordinarily good definition, the air also must have been unusually 
clear and free of tremor. Bat this distinctness is not confined 
to the actual ship, it is also exhibited in the unusual images in 
each of which even the ratlins between the shrouds are seen ; 
that is to say the stratification of the air must have been so 
exquisitely arranged and so undisturbed by fluctuations that 
horizontal lines not an inch in diameter appeared distinct and 
crisp at the distance of 14 miles. 
Now if the stratification had been in concentric layers the 
curvature of these would necessarily have caused great distortion 
in the images, for that curvature bears a large proportion to the 
angular extent of the object. To produce, by any possible 
arrangement of strata, an undistorted image, that arrangement 
must be plane. Here we are face to face with another inconceiv- 
able state of the atmosphere ; the physical explanation bristles 
with impossibilities. 
Although there be no details in measurement, Mr. Yince has 
favoured us with important details in construction. This drawing 
shows, in the first place, the top-mast and parts of the rigging of 
a sloop with the mainsail and jib well filled by the breeze ; the 
foresail is not set ; we must infer that the craft was making way 
enough without it. Here the end of the gaff is connected to the 
top-mast by an elegantly curved line, reproduced in the images. 
In an actual sloop under sail, the gaff is held up by a strong tackle, 
which has to carry the weight of the mainsail, and to resist the 
tension caused by the wind. The resulting strain on the top-mast 
if the arrangement were as in the drawing, would be too great for 
that spar, and appropriate fore-stays would be needed. This part 
of the drawing is not a representation of reality. 
