Various Tesla book cover images

Nikola Tesla Books

Books written by or about Nikola Tesla

Nikola Tesla: Colorado Springs Notes, 1899-1900 Page 222

October 11-13, 1899

Source:
by Professor Aleksandar Marinčić

October 11

Last night Tesla obviously did not sleep much, because he was photographing the oscillator in operation. The photographs were made late in the evening and early in the morning. In the archives of Nikola Tesla museum, several photographs were found which originate from this period but they faded so much that it was not possible to show them. One photograph which is better than others could be seen on Page 221.

Source:
by Professor Aleksandar Marinčić

October 12-13

To calculate the inductance of cylindrical coils Tesla used the formula for a coil of infinite length, which always gave values too large, especially when the diameter: length ratio of the coil was not much less than unity. However, when the proper corrections are made (Russel(57)), the inductances obtained differ from Tesla's values by less than one percent.

Source:
by Professor Aleksandar Marinčić

October 12-13

Tesla measures the impedance of the "special coil", "additional coil", and oscillator secondary. He performs measurements at the frequency of approximately 140 Hz as per method used to determine the impedance module on the basis of voltage and current relationship. He does not explain how he measures resistance (he measured it on Oct. 10). The as found value for "special coils" was compared with the theoretical value determined by means of the equation for an infinitely long coil. The matching of these two values is poor, but this is not surprising because the ratio 1/d is small.

Contents

Introduction
June 1 - 30
July 1 - 31
August 1 - 31
September 1 - 30
October 1 - 31
November 1 - 30
December 1 - 31
January 1 - 7
Commentaries

Appendices: I, II

Images

Glossary

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.