ON LIGHTHOUSE CHARACTERISTICS. 419 



"short-long-short" or "one long" or "one short "as the 

 case may be, suffices, and is intelligible to every one, learned or un- 

 learned, and lets the light be recognised with the greatest ease. As 

 to the distinction between "long" and "short," the contrast be- 

 tween the two, following one of them instantly after the other, is 

 unmistakable. The only cases of the preceding table in which 

 there is not this contrast to show the distinction are the first and 

 second ; but the half-second eclipse of case 2 cannot in practice be 

 ever mistaken for the three-seconds eclipse of case I, which is six 

 times as long. 



It is obvious this plan may be understood 

 immediately by any person learned or unlearned, 

 reading the description, or being told it by word of 

 mouth, and that no knowledge of the Morse letters 

 corresponding to ;he several groups of eclipses is 

 needed. Indeed, if Mr. Preece and others had not 

 let out the secret, I might have brought forward 

 this proposal without any acknowledgment of 

 indebtedness to Morse or to Captain Colomb, had 

 I been disposed to omit to give credit where 

 credit is due for very brilliant and valuable 

 inventions, and had I thought only of the very best 

 way of putting forward my little suggestion in the 

 manner most likely to promote its early adoption 

 by the lighthouse authorities. 



I have only to add, in conclusion, that the 



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