SIGNIFICANCE OF KNOCKING. 125 



things in respect to the boatswain's pipe : first, at the dis- 

 tinctness with which a sound so slender and thin could be 

 heard amidst the wildest commotion of the elements, and 

 also at the great variety of commands that the boatswain 

 could give with his pipe, by means of variations and mod- 

 ulations in the tone of it, which he made by the motion of 

 his hand over a little hole in a part of the pipe from which 

 the air issued. The number and variety of the orders and 

 directions that he could give by this means constituted 

 quite a language. 



In the same way, when he landed in England, John was 

 much interested and amused in observing to how great an 

 extent the knockers on the doors were used as a means of 

 communicating intelligence. A single blow with a knock- 

 er is the rap of " tradespeople," as they call them that is, 

 porters bringing parcels, or messengers from the butchers 

 or grocers, or persons having any thing to sell. A double 

 rap is reserved exclusively for the postman. When that 

 sound is heard everybody in the house knows that the let- 

 ters have come, and the person that attends the door must 

 go at once, so as not to keep so important an official wait- 

 ing. The two strokes generally come very close together 

 rat-tat as quick almost as you could possibly speak 

 those two syllables ; but, however rapidly they are given, 

 so long as there are two, every body knows that it is the 

 postman. Then, if it is a gentleman or lady, whether be- 

 longing to the house or a visitor, there is quite a prolonged 

 rapping, the strokes being usually quite rapid at first, and 

 more deliberate and emphatic at the end more or less so 

 according to the rank and importance of the person knock- 

 ing, thus, Rat-tat-tat-a-tat-tat-tat, tat! TAT! 



Now, in beating such a tattoo as this with the knocker 

 of the door, no two persons, of course, do it alike, and the 

 length and complicateness of the series of strokes admits 



