TEEES AS SHELTER TO GROUJSTD TO THE LEEWARD. 159 



Tlie action of tlie forest, considered merely as a mechanical 

 shelter to grounds lying to the leeward of it, might seem to be an 

 influence of too restricted a chai-acter to deserve much notice; 

 but many facts concur to show that it is a most important ele- 

 ment in local climate. 



It is evident that the efiEect of the forest, as a mechanical im- 

 pediment to the passage of the wind, would extend to a very con- 

 siderable distance above its own height, and hence protect while 

 standing, or lay open when felled, a much larger surface than 

 might at first thought be supposed. The atmosphere, movable as 

 are its particles, and hght and elastic as are its masses, is never- 

 theless held together as a continuous whole by the gravitation of 

 its atoms and their consequent pressure on each other, if not by 



by placing himself on the hill of Capo di Monte at Naples, in the hue of pro- 

 longation of the street called Spaccanapoli. 



It is probably to the stillness of which I have spoken that we are to ascribe 

 the transmission of sound to great distances at sea in calm weather. In June, 

 1853, I and my family were passengers on board a ship-of-war bound up the 

 jEgean, On the evening of the 27th of that month, as we were discussing, 

 at the tea-table, some observations of Humboldt on this subject, the captain 

 of the ship told us that he had once heard a single gun at sea at the distance 

 of ninety nautical mUes. The next morning, though a light breeze had 

 sprung up from the north, the sea was of glassy smoothness when we went on 

 deck. As we came up, an officer told us that he had heard a gun at sunrise, 

 and the conversation of the previous evening suggested the inquiry whether it 

 could have been fired from the combined French and English fleet then lying 

 at Beshika Bay. Upon examination of our position we were found to have 

 been, at sunrise, ninety sea mUes from that point. We continued beating up 

 northwards, and between sunrise and twelve o'clock meridian of the 28th, we 

 had made twelve miles northing, reducing our distance from Beshika Bay 

 to seventy-eight sea miles. At noon we heard «everal guns so distinctly that 

 we were able to count the number. On the 29th we came up with the fleet, 

 and learned from an officer who came on board that a royal salute had been 

 fired at noon on the 28th, in honor of the day as the anniversary of the Queen 

 of England's coronation. The report at sunrise was evidently the morning 

 gun, those at noon the salute. 



Such cases are rare, because the sea is seldom still, and the KVfiaruv aviipvBjiw 

 yelaatm rarely silent, over so great a space as ninety or even seventy-eight 

 nautical miles. I apply the epithet silent to yk'Aaiua advisedly, I am con- 

 vinced that -iEschylus meant the audible laugh of the waves, which is indeed 

 of countless multipUcity, not the visible smile of the sea, which, belonging to 

 the great expanse as one impersonation, is single, though, like the human 

 smile, made up of the play of many features. 



