Testing Pile‐Protecting Compounds.
In 1882 several piles, coated with various patent anti‐teredo coverings, were driven in the harbor of San Francisco for the purpose of testing them. Recently Engineer Manson began pulling up the piles in order to see the result of the experiments. A pile coated with Pearce’s compound, composed of paraffine, limestone, kaolin, etc., was found to be completely honeycombed by the teredos. The eucalyptus and cedar piles were also nearly destroyed. In 1884 the two piles incased by A. W. Von Schmidt in sewer pipe and cement, the twenty‐three coated by Frank Shay with asphalt and wire cloth, the ten of McKeon & Co., coated with warm cement containing a poisonous substance, and those of W. H. Hayes, coated with Portland cement, etc., were examined by Colonel Mendel and Mr. Manson. All showed signs of having proved failures. The insect is ahead of the inventors up to date.