120 MOONLIGHT ON THE SEA. 



Betvveen this sheet of Hght and the observer the 

 waters may be very cahn ; in which case, should the 

 Moon be not very high, another reflection of its beams 

 will be seen not far from the shore ; whilst between 

 it and the sheet of light above alluded to, the sea lies 

 wholly unilluminated : could this portion of the 

 waters repose as quietly as the face of a mirror a dis- 

 tinct and well defined image would be formed, but 

 as there is generally some slight undulation a series 

 of quivering and quickly changing lights are observed. 

 Any one who has seen his face reflected in a mirror 

 made of common window glass will recollect the 

 caricature which exhibited him there with a longi- 

 tude, a twist or an extent of countenance by no means 

 his natural ri^ht, from this appearance he can easily 

 account for the singularly outlined images of the moon 

 on the continually varymg surface of the water. 



Should any thing occur to produce a ripple on the 

 sea between the two enlightened portions, such as 

 the passing of a boat or the rush of a fish curling along 

 the surface, new and vivid images will be reflected 

 from the sides of the newly raised wavelets, and even 

 when these have subsided in the spot where they were 

 first |)roduced yet the extending circles of disturbed 

 water will show them, farther and farther off*, and 

 more or less in number, presenting an appearance of 

 very brilliant stars nsing from the deep, expending 

 the intenseness of their light in an instant, and dying 

 when in contact with the air : or they might perhaps 

 be compared to bubbles of phosphuretted hydrogen, 

 seen from a distance, nsing quickly from the water, 

 to quench with a quick bright gleam. The inten- 

 sity of brilliantness in these images may depend on 

 their being reflected to the eye of an observer from 

 the concave or convex side of a wave, the former of 

 which perhaps may have an effect of concentrating 

 the light as a reflector does when placed behind the 

 flame of a lamp. 



That simple and beautiful law of Catoptrics, which 

 affirms that the angles of incidence and reflection 



