TABLE OF CONTENTS.

MEASURES AND THEIR EQUIVALENTS:

Measures of length.....

Measures of area....

Measures of volume.

Measures of weight..

Measures of work..

Measures of pressure....

Decimal equivalents of parts of an inch..

Wire gauges in mils...

Wire gauges in millimeters..

Tables of specific gravities:

Metals..

Liquids.

Gases..

Weights of substances..

The comparison of thermometers:

Fahrenheit to Centigrade..

Centigrade to Fahrenheit.

Electrical units..

COPPER WIRE:

Formulæ and explanations....

Matthiessen's standard..

PAGE.

123

456789

10

11

11

12

13

13

14-15

16-17

17

18

Temperature coëfficients.

Properties of copper wire-weights, resistances, etc.

IRON WIRE:

Formulæ and explanations......................

Properties of iron wire-weights, strength, resistances, etc.,

Specifications:

Western Union Telegraph company...............

British Post-office.........

Strands:

Formulæ and explanations.........

PAGE.

34

35

36

37

388

Total lengths of wires in spans....

Deflections in spans at various temperatures....

DESCRIPTION OF THE ROEBLING ELECTRIC WIRES:

40

41

42

43

44

45

46

47-49

48

50-52

In these tables the equivalents of the metric system of weights and measures are those given in
1890 by the United States Coast and Geodetic Survey, Office of Standard Weights and Measures. These
values in all the tables are marked by an asterisk (*). The other equivalents are calculated from these.
In the metric system the following prefixes are used for subdivisions and multiples: