The St. Johns herald., 1899-06-24

FACTS ABOUT BARNAcLEs.
Commodore Webster, U. s. N., Write
 of "Fou1 Bottoms"

Commodore Webster, U. s. N., Write,
 of "Fou1 Bottoms"
 The United States cruiser Benning, ton was for some time in the barbor of La Union, in Guatemala, and in six ty-three days there was great growth of barnacles. These growths, as a matter of fact, comprise several varie- ties of shell fish, prominent among which comes the edible oyster. In the case in point, when the Bennington was placed in the dry dock at Mare Island Navy Yard, it was found that oysters large enough for the table were of frequent occurrence.
 These growths must be removed while the ship is in dry dock. If re moved while the ship is adOat, by div CTS, the protecting paint comes off with the barnacle and leaves the metal of the hull unprotected. The regulations of the Navy Department prohibit this being done except in cases of great emergency.
 The barnacle grows to a length of three and four inches, conical in shape, and from the partially closed apex of the cone project pair of strong mandi- bles always in motion, in search of food. These fish are not difficult of re- moval when in dock, for they soon die out of water. Many of the barnacles are pink in color, some are black, and many are white, being specimens of different families. They not only gather and grow on the ships bottom, but even on the propeller and rudder. From experience in the tropics it would seem that the water is full of "spat," or embryo shell fish, necessarily in search of resting place.
 Various paints and mixtures which have been applied to ships bottoms with the object of preventing these growths have not been very successful.
 When a ship has been short time ir tropical waters the bottom presents the appearance of having been sprinkled with sand, the marine life is so evenly distributed. But the tropics are not the only part of the world where ships bottoms get foul. In the waters of Alaska and even further north, animal and vegetable growths interfere with the speed of our ships to an extent lit- tie dreamed of before the advent of steel or iron for ship-building.
 Beside the animal growths of parma cles, oysters and kindred life, a large and rich vegetable growth causes al- most as much trouble. This grass" as it is technically called, is swept away in large measure when the ship steams at full speed, which is not the case with the animal life.
 Ordinarily, a short run in fresh water will kill all of the adherlng growths, when the vegetable matter will drop off, but the shells of dead barnacles re- main to be scraped off in dock. Many of our ships have had their speed re- duced One-half by these growths.
 The remedy for all this expense and trouble is to sheathe the bottom with wood, and then copper that sheathing, as with the old-fashiOned wooden ship.
 The expense of docking and painting a ship of 10000 tons is about $500. AS a safe average the cost of docking our ships, which, as has been said, must take place twice a year, will not be far from $1,000 for each docking, or 5000 year. At the present time there are seyenty-five ships fit for cruising, and requiring this semi-annual dock Ing. A brief calculation shows that these Insignificant little barnacles cost the Treasury Department the tidy sum of not far from $15O,O0 each year. Philadelphia Evening Telegraph.