re a Deep
drainer.--Over-draining of Peaty Soils.--Lincolnshire Fens. Visit
to them in 1857.--56 Bushels of Wheat to the Acre.--Wet Meadows
Subside by Drainage.--Conclusions.

CHAPTER XVIII.

OBSTRUCTION OF DRAINS.

Tiles will fill up, unless well laid.--Obstruction by Sand or
Silt.--Obstructions at the Outlet from Frogs, Moles, Action of
Frost, and Cattle.--Obstruction by Roots.--Willow, Ash, &c., Trees
capricious.--Roots enter Perennial Streams.--Obstruction by
Mangold Wurtzel.--Obstruction by Per-Oxide of Iron.--How
Prevented.--Obstructions by the Joints Filling.--No Danger with
Two-Inch Pipes.--Water through the Pores.--Collars.--How to Detect
Obstructions.

CHAPTER XIX.

DRAINAGE OF STIFF CLAYS.

Clay not impervious, or it could not be wet and dried.--Puddling,
what is.--Water will stand over Drains on Puddled Soil.--Cracking
of Clays by Drying.--Drained Clays improve by time.--Passage of
Water through Clay makes it permeable.--Experiment by Mr.
Pettibone, of Vermont.--Pressure of Water in Saturated Soil.

CHAPTER XX.

EFFECTS OF DRAINAGE ON STREAMS AND RIVERS.

Drainage Hastens the Supply to the Streams, and thus creates
Freshets.--Effect of Drainage on Meadows below; on Water
Privileges.--Conflict of Manufacturing and Agricultural
Interests.--English Opinions and Facts.--Uses of Drainage
Water.--Irrigation.--Drainage Water for Stock.--How used by Mr.
Mechi.

CHAPTER XXI.

LEGISLATION--DRAINAGE COMPANIES.

England protects her Farmers.--Meadows ruined by Corporation
dams.--Old Mills often Nuisances.--Factory Reservoirs.--Flowage
extends above level of Dam.--Rye and Derwent Drainage.--Give Steam
for Water-Power.--Right to Drain through land of others.--Right to
natural flow of Water.--Laws of Mass.--Right to Flow; why not to
Drain?--Land-drainage Companies in England.--Lincolnshire
Fens.--Government Loans for Drainage.

CHAPTER XXII.

DRAINAGE OF CELLARS.

Wet Cellars Unhealthful.--Importance of Cellars in New England.--A
Glance at the Garret, by way of Contrast.--Necessity of
Drains.--Sketch of an Inundated Cellar.--Tiles best for
Drains.--Best Plan of Cellar Drain; Illustration.--Cementing will
not do.--Drainage of Barn Cellars.--Uses of them.--Actual Drainage