Nikola Tesla Books
Books written by or about Nikola Tesla
inductance of the primary circuit. Now with reference to the table of inductances the inductances in experiments 1, 2, 3, and 4, respectively, were: 12,824, 12,463, 12,247 and 12,103 cm. The increase of distance from 1 to 2 was 160%; from 2 to 3 61.5%; from 3 to 4 38.2%. Putting results together we have:
| Increase of distance | Amount of the diminution of capacity | |
|---|---|---|
| 2' | 160% | 361 |
| 2' | 61.5% | 216 |
| 2' | 38.2% | 144 |
The numbers indicate a general proportionality but now the capacity of the excited system should be known.
This will be followed up.
* Capacity of primary cables with reference to earth should be determined.
Colorado Springs
Dec. 8, 1899
In response to note from I. Hawthorne forwarded to “Northamerican” Philadelphia, dispatch as follows:
“In response to a request from friend I. Hawthorne the following statement:
“Confining myself to my chosen sphere, I believe that the mastery of electrical forces was as great and beneficial an achievement as the Century has witnessed. As to the immediate future my thoughts are dominated by two ideas, one of which is already realized, while the other is on the eve of accomplishment. The art of governing the movements and performances of distant automatons, enabling machines to act as creatures endowed with a mind, will demonstrate to the leading nations the futility of armaments and impracticability of the present life destroying implements of war and will lead to more permanent peaceful relations, in harmony with the humanitarian spirit and enlightenment of the age; while the art of transmitting electrical energy through the natural media, without the use of leading wires, over vast distances, from great centers, as Niagara, will open up inexhaustible resourses of wealth and power and, by rendering immense amounts of the energy of the sun available to the wants of man, will perhaps make it possible for him to produce similar wonderful changes and transformations on the surface of our globe as are, to all evidence, now being wrought by intelligent beings on a neighbouring planet.”
N. Tesla
Experiment to determine the inductance of coil wound on the square frame before used by means of resonance analysis and another known coil:
The square coil was connected in series with coil of 344 turns as before and maximum rise was determined in the same way as described in preceding experiments. The resonant condition was obtained with
314
December 7-10
Tesla wants to determine the influence of the ground conductor, on the resonance transformer of the oscillator. He performs the measurements on a circuit which is made in the shape of a rectangular frame and its position could be changed in relation to the ground surface. The rectangular frame is wound with 14 turns and connected in series with the coil of 344 turns. One terminal of the coil frame is grounded. He does not give complete information how these coils are connected with the oscillator. He determines the oscillator frequency change when the coil frame is at various elevations above the ground.
He draws the conclusion that the resonant frequency of the tested circuit is increased with the increased elevation of the rectangular coil. On the basis of that he draws the conclusion that: a) The ground does not act as a good conductor (coil in the vicinity of a conductive plane has smaller inductance due to induced currents); b) The capacitance of the coil towards the ground is a significant factor. The conclusions Tesla develops on Dec. 8 and 9 are correct, because it is a question of relative determination of the values, even if there would be a secondary influence which does not allow secure oscillator frequency determination.
On Dec. 9 Tesla attempted to calculate the coil self-capacitance in the tested circuit as per previously described method (please see June 28), but he very soon ended the discussion without giving a complete answer to the problem as a whole.
