| B.W.G. No. | Diameter in Millimetres. | Area in Millimetres. | Circumference in Millimetres. | Metres per Kilogramme. | Kilogrammes per Metre. |
|---|---|---|---|---|---|
| 1 | 7.62 | 45.6 | 23.9 | 1ᵐ.95 | 0ᵏ.514 |
| 2 | 7.21 | 40.8 | 22.6 | 2.78 | 0.360 |
| 3 | 6.58 | 34 | 20.7 | 3.33 | 0.300 |
| 4 | 6.04 | 28.7 | 19 | 3.95 | 0.253 |
| 5 | 5.59 | 24.5 | 17.6 | 4.61 | 0.217 |
| 6 | 5.16 | 21 | 16.2 | 5.43 | 0.184 |
| 7 | 4.57 | 16.4 | 14.3 | 6.90 | 0.145 |
| 8 | 4.19 | 13.8 | 13.1 | 8.20 | 0.122 |
| 9 | 3.76 | 11.1 | 11.8 | 10.20 | 0.098 |
| 10 | 3.40 | 9.1 | 10.7 | 12.50 | 0.080 |
| 11 | 3.05 | 7.3 | 9.6 | 13.50 | 0.074 |
| 12 | 2.77 | 6 | 8.7 | 18.87 | 0.053 |
| 13 | 2.41 | 4.6 | 7.6 | 24.80 | 0.0403 |
| 14 | 2.11 | 3.5 | 6.63 | 32.40 | 0.0309 |
| 15 | 1.83 | 2.63 | 5.75 | 45.10 | 0.0232 |
| 16 | 1.65 | 2.14 | 5.18 | 52.90 | 0.0189 |
| 17 | 1.47 | 1.70 | 4.62 | 69.40 | 0.0144 |
| 18 | 1.24 | 1.21 | 3.90 | 94.30 | 0.0106 |
| 19 | 1.07 | 0.9 | 3.36 | 135.10 | 0.0074 |
| 20 | 0.89 | 0.62 | 2.80 | 181.8 | 0.0055 |
| 21 | 0.81 | 0.51 | 2.54 | 212.8 | 0.0047 |
| 22 | 0.71 | 0.39 | 2.23 | 285.7 | 0.0035 |
| 23 | 0.63 | 0.31 | 1.98 | 364 | 0.0028 |
| 24 | 0.55 | 0.24 | 1.73 | 465 | 0.00215 |
| B.W.G. No. | Resistance in Ohms | Kilogrammes per Ohm. | Metres per Ohm. | |
|---|---|---|---|---|
| per Kilogramme. | per Metre. | |||
| 1 | 0.00073515 | 0.0003777 | 1360 | 2652 |
| 2 | 0.00116760 | 0.000420 | 860 | 2379 |
| 3 | 0.00168165 | 0.000505 | 595 | 1980 |
| 4 | 0.00232260 | 0.000588 | 430 | 1700 |
| 5 | 0.03227000 | 0.000700 | 310 | 1430 |
| 6 | 0.00452319 | 0.000833 | 220 | 1200 |
| 7 | 0.00731400 | 0.00106 | 137 | 945 |
| 8 | 0.01025000 | 0.00125 | 98 | 802 |
| 9 | 0.01581000 | 0.00155 | 63 | 646 |
| 10 | 0.0237500 | 0.00190 | 42.20 | 527 |
| 11 | 0.0318600 | 0.00236 | 31.40 | 424 |
| 12 | 0.0539682 | 0.00286 | 18.60 | 350 |
| 13 | 0.0932480 | 0.00376 | 19.70 | 266 |
| 14 | 0.160380 | 0.00495 | 6.26 | 202 |
| 15 | 0.294954 | 0.00654 | 3.40 | 153 |
| 16 | 0.430077 | 0.00813 | 2.30 | 123 |
| 17 | 0.73564 | 0.0106 | 1.35 | 94.5 |
| 18 | 1.33906 | 0.0142 | 0.75 | 70.4 |
| 19 | 2.60743 | 0.0193 | 0.38 | 51.9 |
| 20 | 5.05404 | 0.0278 | 0.20 | 36 |
| 21 | 7.04368 | 0.0331 | 0.14 | 30.2 |
| 22 | 12.37081 | 0.0433 | 0.08 | 23.1 |
| 23 | 19.6924 | 0.0541 | 0.05 | 18.5 |
| 24 | 32.5500 | 0.0700 | 0.03 | 14.3 |
For Table of English Measurements [see page 105].
EXPLANATION OF TERMS.
Accumulator.—Another name for secondary batteries.
Alternate Current Dynamo.—Produces currents which are alternately positive and negative.
Amalgamation.—Zinc is protected from local action by having its surface coated with mercury.
Ampère.—The Unit of current. A volt divided by an ohm.
([See Electrical Measurements, page 104].)