Chapter II: Part II

I. Some Practical Advice 271
The inventor, ancient and modern--Barriers to mechanical progress
in the past--Laws of gravitation--How to adjust sewing machines.

II. Mechanical Movements 306
Coffee mills--Pulleys--Pumps--Pistons--Levers--Steam engine and
water wheel governors, etc.

III. The Weather and Indoor Work 349
How to make a rain gauge--Hail--Snow--Designing, making
and inflating paper balloons--Magnetized watches--A boy's
wheelbarrow--Vacuum cleaners.

IV. Motors and Typewriters 387
Motors, gasolene and steam--Automobile frames--The modern
typewriter--Directions for securing copyrights.

ILLUSTRATIONS

A Motor-Boat Model _Frontispiece_

FACING PAGE

Boat-House and Workshop 42
The Creek 70
Making a Motor Launch 88
Finishing the Motor Launch 112
The Monoplane Model Complete 160
Making an Aeroplane Model 180
Making Kites 190
A Sundial Made of Concrete 208