Various Tesla book cover images

Nikola Tesla Books

Books written by or about Nikola Tesla

Capacity of structure without hood before found with extra coil was 311.2 cm, hence for hood alone we get 366.7-311.2=55.5 cm. From first and last reading it appears that the secondary capacities in the two cases were as $! {168 \over 39} $!. Now the capacity of excited system in last reading was

C's2 = $! {{0.0351 \times 72,661} \over {2 \times 10^{7}}} $! mfd, or C's2 = 144.77 cm.

From this would follow value

C's1 = $! {168 \over 39} $! x 114.77 = 494.39 cm.


C's1 - C's2 = 494.39 - 114.77 = 379.62 cm.

This value does not agree quite closely with that before found but the tuning was not quite exact in last case.

Note: It now seems that the tuning in all previous cases when structure was determined was made to the first octave instead of to the fundamental tone. This is to be ascertained. If this be so then capacity would be much greater.


November 26

He gives the description of some details of the structure with metal sphere on top. He measures the capacitance of this system in combination with a coil with 344 turns and a new "additional coil". Earlier, on Nov. 7, he performed the capacitance measurement of the same structure, but without protective cover, and with the "additional" and experimental" coils. On Nov. 12 he performed similar measurement with coil of 1314 urns, and on Nov. 26 he recalls results of Nov. 7 with new "additional" coil. In the notes there is one more result with the "additional" coil, with the most improved method of determining resonance (please see Nov. 13). This result, which otherwise is quite different from others, is not mentioned on Nov. 26.

There is a remark at the end of the notes of Nov. 26 when he foresees the possibility of systematic errors in determining the resonant frequency and Tesla emphasized that this has to be checked.


Lowercase tau - an irrational constant defined as the ratio of the circumference of a circle to its radius, equal to the radian measure of a full turn; approximately 6.283185307 (equal to 2π, or twice the value of π).
A natural rubber material obtained from Palaquium trees, native to South-east Asia. Gutta-percha made possible practical submarine telegraph cables because it was both waterproof and resistant to seawater as well as being thermoplastic. Gutta-percha's use as an electrical insulator was first suggested by Michael Faraday.
The Habirshaw Electric Cable Company, founded in 1886 by William M. Habirshaw in New York City, New York.
The Brown & Sharpe (B & S) Gauge, also known as the American Wire Gauge (AWG), is the American standard for making/ordering metal sheet and wire sizes.
A traditional general-purpose dry cell battery. Invented by the French engineer Georges Leclanché in 1866.
Refers to Manitou Springs, a small town just six miles west of Colorado Springs, and during Tesla's time there, producer of world-renown bottled water from its natural springs.
A French mineral water bottler.
Lowercase delta letter - used to denote: A change in the value of a variable in calculus. A functional derivative in functional calculus. An auxiliary function in calculus, used to rigorously define the limit or continuity of a given function.
America's oldest existing independent manufacturer of wire and cable, founded in 1878.
Lowercase lambda letter which, in physics and engineering, normally represents wavelength.
The lowercase omega letter, which represents angular velocity in physics.