PROCEEDINGS OF THE rOLYTECHNIC ASSOCIATION. 601 



which he felt in cold and stormy nights in the winter, when he knew that 

 many a poor fellow was depending on him, and his lamps burned dimly, 

 the oil being chilled. Sometimes he was obliged to warm the oil in a ket- 

 tle in liis house at midnight, and fill his lamps over again; for he could 

 not have a fire in the lighthouse, it produced such a sweat on the windows. 

 His successor told me that he could not keep too hot a fire in such a case. 

 All this because the oil was poor. A Government lighting the mariners 

 on its wintry coast with summer-strained oil, to save expense! That were 

 surely a summer-strained mercy. 



" This keeper's successor, wlio kindly entertained me the next year, 

 stated that one extremely cold night, when this and all the neighboring 

 lights were burning summer oil, but he had been provident enough to 

 reserve a little winter oil against emergencies, he was waked up with 

 anxiety and found that his oil was congealed and his light's almost extin- 

 guished; and when, after many hours' exertion, he had succeeded in replen- 

 ishing his reservoirs with winter oil at the wick* end, and with difficulty 

 had made them burn, he looked out and found that the other lights in the 

 neighborhood, which were usually visible to him, had gone out, and he 

 heard afterward that the Planet River and Billingsgate lights also had 

 been extinguished. 



"Our host said that the frost, too, on the windows, caused him much 

 trouble, and in sultry summer nights the moths covered them and dimmed 

 his lights; sometimes even small birds flew against the thick plate glass, 

 and were found on the ground in the morning with their necks broken. In 

 the spring of 1855 he found nineteen small yellow birds, perhaps gold- 

 finches or myrtle birds, thus lying dead around the lighthouse; and 

 some times in the fall he had seen where a golden plover had struck 

 the glass in the night, and left the down and the fatty part of its breast 

 on it. 



"Thus he struggled by every method to keep his light shining before 

 men. Surely the lighthouse-keeper has a responsible, if an easy, office. 

 When his lamp goes out, he goes out; or, at most, only one such accident 

 is pardoned. 



" I tliought it a pity that some poor student did not live there, to profit 

 by all that light, since he would not rob the mariner. 'Well,' he said, 'I 

 do sometimes come up here and read the newspaper when they are noisy 

 down below.' Think of fifteen Argand lamps to read the newspaper by! 

 Government oil! light enough, perchance, to read the Constitution by! I 

 thought that he should read nothing less than his bible by that light. I 

 had a classmate who fitted for college by the lamps of a lighthouse, which 

 was more light, we think, than the University afforded." 



Wave-Motions. 



Let us, in imagination, stand with Thoreau on the luminous tower and 

 amid the agitations of ocean, air and seth, consider the laws by which the 

 Presiding Power controls these elements. The restless sea, through all its 

 movements, from ripple to billow, obeys the same mandate; the tfme of 

 each oscillation is proportional to the square root of the length of the 

 Wave. At great depths the motion of the fluid is wholly insignificant, 



