## Nikola Tesla Books

Books written by or about Nikola Tesla

# Nikola Tesla: Colorado Springs Notes, 1899-1900Page 259

November 5, 1899

Nov. 5, 1899

Capacity of structure of iron pipes, before described, computed:

7" pipe: Outside diam. 7.625" = 19,3673 cm = d

length of pipe with cap = l = 23' 4" = 280" = 811.2 cm = l

 C1 = $! {l \over {2 \log_{e} {l \over r}}}$! = $! {811.2 \over {2 \times 4.42313}}$! r = 9.6837 $! {l \over r}$! = 83.77 C1 = 91.7 cm. $! {\log_{e} {l \over r}}$! = 1.9231 x 2.3 = 4.42313

6" pipe: Outside diam. = 6.625" = 16.8275 cm = d

length of pipe 18' 2" = 218" = 553.72 cm = l

 C2 = $! {l \over {2 \log_{e} {l \over r}}}$! = $! {553.72 \over {2 \times 4.182}}$! r = 8.4138 $! {l \over r}$! = 65.81 C2 = 66.2 cm. $! {\log_{e} {l \over r}}$! = 1.818292 x 2.3 = 4.182

5" pipe: Outside diam. 5.563" = 14.13 cm = d

length of pipe 18' 4 1/2" = 220.5" = 560.07 cm = l

 C3 = $! {l \over {2 \log_{e} {l \over r}}}$! = $! {560.07 \over {2 \times 4.368}}$! r = 7.065 $! {l \over r}$! = 79.27 C3 = 64.11 cm. $! {\log_{e} {l \over r}}$! = 1.89911 x 2.3 = 4.368

4" pipe: Outside diam. 4.5" = 11.43 cm = d

length of pipe 15'7 1/4" = 187.25" = 475.615 cm. = l

 C4 = $! {l \over {2 \log_{e} {l \over r}}}$! = $! {475.615 \over {2 \times 8.832}}$! r = 5.715 $! {l \over r}$! = 83.22 C4 = 53.85 cm. $! {\log_{e} {l \over r}}$! = 1.92 x 2.3 = 4.416

17*

259

November 5

Photographs of the Colorado Springs laboratory always show the pole rising from the center of the building. Its dimensions are given in the entry of 17 October. Now Tesla calculates the capacity of the pole as the sum of the capacities of its parts of different thickness, using the formula first cited on October 28th. His final remark indicates that he had thoroughly understood the physical essence of the phenomenon.

## 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;