## Nikola Tesla Books

Books written by or about Nikola Tesla

# Nikola Tesla: Colorado Springs Notes, 1899-1900Page 225

October 15-16, 1899

as secondary period of the coil with ball or

$! {T_{s} = {0.8164 \over 10^{5}} = {81.64 \over 10^{7}}}$!   Now Tp was = $! {267 \over 10^{7}}$!, from this

$! {{T_{s} \over T_{p}} = {81.64 \over 267} = 0.306 = {\sqrt{38.1 \over 38.1 + C}}}$! from previous analogy - and from this

$! {0.306^{2} = {38.1 \over {38.1 + C}}}$! or $! {C = {38.1 \over 0.09364} - 38.1 = {{38.1 \times 0.90636} \over 0.09364} = 38.1 \times 9.68 = 368.8}$!

Now

$! {T_{p}' = {{2 \pi \over 10^{3}} \sqrt{0.04 \times {368.8 + c \over {9 \times 10^{5}}}}}}$! and $! {T_{p}'' = {{2 \pi \over 10^{3}} \sqrt{0.04 \times {368.8 + c' \over {9 \times 10^{5}}}}}}$!

but $! {T_{p}'' = {279 \over 10^{7}}}$! and from this

$! {{T_{p}' \over T_{p}''} = {267 \over 279} = {\sqrt{{0.04 \times {{368.8 + c} \over {9 \times 10^{5}}}} \over {{0.04 \times {{368.8 + c'} \over {9 \times 10^{5}}}}}}}}$!   $! {1.045 = 279 \over 267}$! and from this

$! {(1.045)^{2} = {368.8 + c' \over 368.8 + c}}$! now c = 38.1

$! {1.092 \times (368.8 + 38.1) = 368.8 + c'}$! and

$! {c' = 368.8 \times (1.092 - 1) + 38.1 \times 1.092 = 75.53}$! cm.

This value is but little smaller than that before found. From this result it would then appear that by lifting the sphere from 33.66 to 34.66 feet the capacity was increased from 38.1 to 75.53 cm, or approximately 98.3%, a trifle less than before found.

Oct. 16, 1899

Inductance of secondary modified by winding another wire No. 10 in multiple with the first. All other particulars remaining:

Readings: I = 7.1   E = 60.5   R = 1.382   ω = 880

$! {E \over I = 8.521}$!

$! {L = {\sqrt{8.521^{2} - 1.382^{2}}} = {\sqrt{70.6975} \over 880}}$!

15

225

October 15

Because of the arithmetical error made on October 9th (see commentary), he mistakenly concludes that the capacities of the ball are now somewhat less than before. Had he used the correct values, his conclusion would have been just the opposite.

October 15

He continues the measurements from Oct. 9 with corrections in parameters according to the results obtained on Oct. 12. Due to a calculation error made on Oct. 9, he draws the wrong conclusion that the newly obtained sphere capacitances are somewhat smaller than the previous one. With accurate values the conclusion would be exactly opposite.

## 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 &amp; Sharpe (B &amp; 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&nbsp;angular velocity in physics.&nbsp;