360 ANNUAL OF SCIENTIFIC DISCOVERY. 



them or the wood is broken, and they die or waste away in their alcoves. In 

 the harbor of New York I suppose their development commences some time 

 about the first of July. I am not sure, but I believe that they will keep 

 developing the whole year in the waters as far south as Charleston, S. C., as 

 well as in all the warm climates, the "West and East Indies, &c. In the har- 

 bors of Boston and Portsmouth, New Hampshire, where we have Navy Yards, 

 the worm does but little injury. Piles driven for any of the bridges crossing 

 from Boston to Charlestown, or crossing the river from Portsmouth to Kittery, 

 Maine, will not be injured in a number of years ; the worm in those harbors 

 is small in appearance, like vermicelli threads used in soups. The damage 

 done to piles in those harbors is at high and low water marks ; there seems 

 to be a pause when the tide is done running up or down, and at those two 

 points only are these animals mischievous in those harbors. It is said that 

 they are not as destructive near the New York city side, either in the North 

 or East river, as they are on the Brooklyn side or the Jersey side. I have 

 seen wood seriously injured on the Long Island (Brooklyn) side; and have 

 been well informed that the piles driven at the different ferries on the New 

 York city sides (North and East) are but little damaged, compared to the 

 injury done in the Bay betwixt the Navy Yard, at Brooklyn, and the city of 

 TTilliarnsburg, Long Island. One thing is certain : all vessels employed in the 

 New York trade should be protected from these enemies to commerce. I 

 suppose the cause of the worm not developing near the wharves of the city, 

 is the great quantity of filth which must run off into the river, and may act 

 as. poison to the animal. In the harbor of Baltimore, as high as the basin, the 

 worm does not appear, and as far down in the harbor as Fell's Point, the 

 animal does but little damage. Rafts of timber remain in the docks ah 1 the 

 summer months, without being injured. It is not advisable to risk a vessel's 

 bottom, unprepared, as low down as Fort McHenry; and nowhere in the 

 Chesapeake Bay. I believe it dangerous to risk, unprepared, vessels' bottoms 

 in any river or inlet five miles from its mouth, that empties into the Chesa- 

 peake. 



In the harbors of Boston and Portsmouth, N. H., it is unnecessary for piles 

 to be charred, or to have the bark on, or to have paint and other substances 

 on them ; for the timber is secure from serious damage by the shell-fish for 

 twenty-five years, and that will be as long as the timber exposed to open air 

 will continue clear of other decay. I would prepare or leave the bark on all 

 the piles which I should drive in the harbors of New York and Baltimore ; 

 for I believe that in a very dry season the worm will develope in the harbor 

 of Baltimore below the basin. There have been such seasons. I am sure it 

 will be found to be more safe to have all the piles driven near the wharves 

 of New York city, on the East or North river, prepared against the salt- 

 water worm. In this harbor and its vicinity, it is positively necessary that 

 the piles be protected, that is, that they are driven in bark, or preserved in 

 another manner as made plain in this communication. 



The bottom plank of a ship unprotected here, and kept submerged one sum- 

 mer, will be destroyed. The inside, that is, the wood betwixt the out and 

 inside surface of the plank, will be riddled to a honey-comb in appearance ; 



