Various Tesla book cover images

Nikola Tesla Books

Books written by or about Nikola Tesla

Nikola Tesla: Colorado Springs Notes, 1899-1900 Page 227

October 17, 1899

15*

227

Source:
by Professor Aleksandar Marinčić

October 17

The 122 ft metal pole bearing the 30" ball is the antenna to be seen in the middle of the laboratory on many photographs. The bottom end of the antenna is insulated by a wooden pole. This is a single-pole antenna of small electrical length. At around the highest frequencies which Tesla used the h/λ ratio was about 0.015. The terminal capacity made the effective height somewhat greater than h, but it still remained an electrically short antenna.

Source:
by Professor Aleksandar Marinčić

October 17

He gives a description of a metal pole 43.3 meters in height with a metal globe 67.2 cm in diameter at the top. This is the aerial which could be seen in the middle of the laboratory on the many photographs. The insulator at the bottom of the aerial is a wood-pole stub. The structure is actually a monopole aerial of small electrical length. At the approximate maximum frequencies with which Tesla operated, the ratio H/λ). is approx. 0.015. Due to the terminal capacitance the effective aerial height is somewhat larger than H/2 but even in that case an electrically small aerial is being questioned. The main reason for the construction of this aerial is the testing of the "vibrations in the ground".

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.