OIL1AG THE WAVES. 287 



Franklin was not a man to remain prejudiced; he ac- 

 cordingly investigated the subject, aft.d the results of his 

 experiments, made upon a pond on Clapham Common, 

 were communicated to the Koyal Society. He states that 

 after dropping a little oil on the water, " I saw it spread 

 itself with surprising swiftness upon the surface, but the 

 effect of smoothing the waves was not produced; for I had 

 applied it first upon the leeward side of the pond, where 

 the waves were largest, and the wind drove my oil back 

 upon the shore. I then went to the windward side, where 

 they began to form; and there the oil, though not more 

 than a teaspoonful, produced an instant calm over a space 

 several yards square, which spread amazingly, and extended 

 itself gradually till it reached the lee side, making all that 

 quarter of the pond (perhaps half an acre) as smooth as a 

 looking-glass." 



Franklin made further experiments at the entrance of 

 Portsmouth Harbor, opposite the Haslar Hospital, in com- 

 pany with Sir Joseph Banks, Dr. Blagden, and Dr. Solan- 

 der. In these experiments the waves were not destroyed, 

 but were converted into gentle swelling undulations with 

 smooth surfaces. Thus it appeared that the oil destroys 

 small waves, but not large billows. 



Franklin's explanation is, " that the wind blowing over 

 water covered with a film of oil cannot easily catch upon it, 

 so as to raise the first wrinkles, but slides over it and leaves 

 it smooth as it finds it." 



Further investigations have since been made which con- 

 firm this theory. The first action of the wind in blowing 

 up what the sailors call " a sea," is the production of a rip- 

 ple on the surface of the water. This ripple gives the 

 wind a strong hold, and thus larger waves are formed, but 

 on these larger there are smaller waves, and on these 

 smaller waves still smaller ripples. All this roughness of 

 surface goes on helping the wind, till at last the mightiest 

 billows are formed, which then have an oscillation inde- 

 pendent of the wind that formed them. Hence the oil 

 cannot at once subdue the great waves that are already 

 formed, but may prevent their formation if applied in time. 

 Even the great waves are moderated by the oil stopping 



