PART I

CHAPTER PAGE

I. A Pathway of Cement 3 Purchasing property, River Passaic--Removing rocks and other obstacles--Preparing for cement sidewalk--Digging trench and purchasing materials--Making, laying, and properly placing concrete--The lever and roller and application--Moving heavy bodies with lever and roller--Finishing the cement sidewalk--How to make good concrete walks.

II. Building of a Boat House 36 Qualities of the inclined plane--Dismantling an old barn and out-houses--Blocks and tackle, ropes and pulleys--Strength and care of ropes--Building a boat-house, using old materials--Strength of timber floors--Method of construction--Holding power of nails--Doors and windows for boat-house--The use of rollers in moving heavy weights--Sliding ways for boat--How heavy stones were raised to tops of Egyptian Pyramids.

III. Bridge and Boat Work 65 Dimensions of the launch--Arrival of The _Mocking-Bird_--An interesting boat talk--A sail on the river--Building a small foot-bridge--The same completed--Some rules for sailing a launch--Fitting up boat-house and dock--Preparing block for keel--The winch and its construction--The wheel and axle as a mechanical power--The fusee, and what it means--Some problems solved.

IV. Making a Gasolene Launch 84 Arrival of boat material--Laying keel and keelson--Setting up the boat and giving her shape--Laying engine bed--Installing engine and propeller--Nailing on planking--Table of offsets--Gasolene engine and carburetor--Dimensions of engine and propeller--Gas engines, generally--Danger of using gasolene--The proper use of yacht flags for signalling.

V. A Talk About Engines 110 Water around the cylinder--The carburetor and spark coil--Running the engine in boat-house--Varnishing the boat--A steamboat on the river--A story of the first steam engine--How the steam acted in the case--The slide valve, piston and steam chest--Internal and external engine heaters--Horse-power and how calculated--Foot pounds, dry steam and condensation--Expansion of gases, turbines--Gilding the name--Constructing picnic tables and seats--Height of tables, chairs and benches.

VI. Propeller and Other Screws 136 The launch of the _Caroline_--Trial of the new boat--Description of the screw as a power--The wheel and worm and endless screw--Formula for counting power of wheel and worm screws of various kinds--Archimedian screw and water lifter--Some data of power of "wheel and worm"--The screw propeller, with data--How to calculate force of propeller screws--Finding pitch and other lines for propeller--The screw auger or boring tool--Adhesion of ordinary wood screws--How to loosen and withdraw rusty screws.

VII. Aeroplanes 158 Seats for riverside--Model aeroplane for the "Fourth"--Dimension on construction of planes--Why a monoplane rises from the earth--The gyroscope as a balancer--The biplane and its construction--Aeroplanes generally--The French aeroplane "Demoiselle"--How to make a model aeroplane--Illustrations and details of model aeroplane--Some general remarks.

VIII. Kites, Sundials, Patents 185 The theory of kite-flying--The highest kite ascent--The flat plane kite--The kite a small aeroplane--A box kite of common type--Cellular kites of various kinds--Pairs and bevies of kites--Bird flight and motion--War kites of various kinds--Wind gauges and wind force--Patents and how to secure them--A simple sundial--How to make an oval flower bed.

IX. Tides 212 The "why" of the tides explained--Globular form of the earth proved--Day and night--Phases of the moon--Attraction of the sun and moon--Newton's theory of the tides--Height of tides--A simple hygrometer--The Australian boomerang--Theory of the pump.

X. Wall Making and Plumbing 237 Protecting the river bank--Concrete retaining walls--Big dams in the West--Galveston sea wall--The great dam across the Nile--Proposed irrigation works in Babylon--Some properties of light and sound--Hints on amateur plumbing--The peppermint test--Barometers of various kinds--Thermometers, and their uses--Something about steel springs--How to make a cross-bow--The gyroscope and its uses.