smal failure. After a good deal of inquiry, your committee
has been enabled to obtain information of the results of three of these
experiments.

The pine paving blocks upon Pennsylvania Avenue (experiment 23) were
first kiln-dried, and then immersed in a hot solution of sulphate of
iron.

The spruce blocks on E Street (experiment 24) were treated with chloride
of zinc, or, in other words, burnettized; but the mode of application is
not stated.

The pine blocks upon Sixteenth Street (experiment 25) were treated with
the residual products of petroleum distillation. It is stated that this
was the only process in which pressure was used.

In from three and a half to four and a half years the blocks were badly
decayed, and large portions of the streets were almost impassable, while
other streets paved in the same year with untreated woods remained in
fair condition.

It has been stated to your committee that this result, which did much
toward bringing all wood preserving processes into contempt, was chiefly
owing to the very dishonest way in which the preparation was done; that
in fact there was a combination between the officials and the
contractors by which the latter were chiefly interested "how not to do
it," and that the above results, therefore, prove very little on the
subject of wood preservation.

Through the kindness of the United States Navy Department your committee
is enabled to give the results of a series of experiments (Nos. 26 to 41
inclusive) which have been carried on at the Norfolk, Va., Navy Yard,
for a series of years, by Mr. P.C. Asserson, Civil Engineer, U.S.N., to
test the effect of various substances as a protection against the
_Teredo navalis_. It will be noticed that the application of two coats
of white zinc paint, of two coats of red lead, of coal tar and plaster
of Paris mixed, of kerosene oil, of rosin and tallow mixed, of fish oil
and tallow mixed and put on hot, of verdigris, of carbolic acid, of coal
tar and hydraulic cement, of Davis' patent insulating compound, of
compressed carbolized paper, of anti-fouling paint, of the Thilmany
process, and of "vulcanized fiber," have proved failures.

The only favorable results have been that oak piles cut in the month of
January and driven with the bark on have resisted four or five years, or
till the bark chafed or rubbed off, and that cypress piles, well
charred, have resisted for nine years.

This merely confirms the general conclusion w