Tesla 1894 Plates: 72 Engravings, Cited Page by Page

The 1894 File · a linkable asset. Every plate below is cited to the page the book prints it on.

Published: October 27, 2026  |  Updated: October 27, 2026

This page carries 72 engravings and photographs from the 1894 first edition of The Inventions, Researches and Writings of Nikola Tesla, edited by Thomas Commerford Martin. Every plate on it is cited three ways: the figure number the book sets under the plate, the page number the book prints in its own corner, and the chapter the book puts it in. None of them is captioned from a file name.

Public domain (1894 imprint). Reuse freely; a credit line is appreciated.

The grid is grouped by the four parts of the volume and, inside each part, by chapter and printed page, so it reads as the book rather than as a pile of pictures. Each plate links to the full file, and the whole set comes as one ZIP.

Citing a Plate From This Page

The credit line we would like, and the one the ZIP's README prints:

Plate, Martin (ed.), The Inventions, Researches and Writings of Nikola Tesla (1894), p. 378.

The number in that line is the number the book prints, not the number of the page of the scan we worked from. Our scan runs eighteen leaves ahead of the printed folios, so the printed page is the scan file number minus 18. That rule is worth stating because it is the most common way a citation like this goes wrong: a file called p396 in a folder of page scans is the plate the book prints on page 378, and a citation that says 396 sends a reader to a page of the volume that carries different writing altogether.

Every caption on this page states the printed page. The file names behind the files are a different matter, and they are kept in the selection record rather than in front of the reader, because a file name records where a crop was cut from, which is not the same fact as what a plate is.

The Book Names Its Own Plates

The volume points at its own engravings in its own prose, which is where the figure numbers on this page come from. On printed p. 378, in the chapter on high frequency and high potential currents, the text says: "Figs. 204 and 205 illustrate a machine in which the armature conductor and field coils are stationary, while the field magnet core revolves" (1894, p. 378). The next sentence separates the next plate from it: "Fig. 206 shows a machine embodying the same plan of construction, but having a stationary field magnet and rotary armature" (1894, p. 378).

A 1894 engraving, Fig. 205, printed p. 378: plan view of a machine with two square coil groups on a frame, a shaft and a flywheel

Chapter XXX does the same thing about the two plates that open it. Tesla writes that he "devised various forms" of apparatus "of which two are illustrated in the accompanying engravings" (1894, p. 392), and then, one printed page later, names the second one: "Another form of apparatus is illustrated in Fig. 209" (1894, p. 393). The footnote on that first page says where the chapter came from: "Article by Mr. Tesla in The Electrical Engineer, N. Y., May 6, 1891" (1894, p. 392). That is also why the plates do not look like one set. They came in with the articles they were drawn for, from several magazines and several years, and the volume reprinted them.

A 1894 engraving, Fig. 208, printed p. 392: a ring lined inside with two sets of tin-foil coatings, and inside it a cylinder carrying the matching coatings, both led out to two ring terminals

The volume is also the source for the plainest caution about using these plates as evidence. The Appendix chapter that reprints the World's Fair exhibit says of the models on its own table: "All these models shown represent early work, and the enlarged engravings are made from photographs taken early in 1888" (1894, p. 483). It then says the plate fails some of them: "There is a great number of other models which were exhibited, but which are not brought out sharply in the engraving, Fig. 297" (1894, p. 483). A plate is a plate. The book says so, on the page that discusses the very engraving reproduced below, and a caption that promises more than the print gives is not a citation, it is a claim.

A 1894 halftone, Fig. 297, printed p. 478: a long table of motors, rings and coils at the World's Fair personal exhibit, with a railing in front

The extractor that cut our crops named each one for the figure string nearest the crop in the scan's text layer, and a page that mentions figures in its body paragraphs confuses that. Printed p. 14 is the clearest case: the plate the extractor cut from that scan page is captioned FIG. 7. and FIG. 7a. by the book, while the same page's text layer contains a body sentence that mentions Fig. 9, and the file came out called fig9. A caption read from the strip of print under the plate gets it right; a caption read from the file name does not.

How These 72 Were Chosen

The plates were catalogued before they were chosen. The file called manifest_qc.csv, in the website/assets/tesla1894/ folder of this site, holds 223 crops, each with a verdict, a subject line written while looking at the crop, an A/B/C quality grade, and a note of whether the aspect and the printed figure number had been checked. This page reads that file and applies five rules, and the rules are printed here because they are what makes the page citable rather than merely pretty.

  • The row must be a keeper and the plate must be A or B quality. C-grade crops are

out: they are the ones the QC pass found badly scanned, badly cropped or badly exposed.

  • The printed figure number must be settled. A row that flags its own number as

mis-read, contradicted or unsettled cannot carry a number in a caption, so it carries no plate here.

  • The file must be one of the book's own figures. Page-scan crops and downloaded

patent sheets live in the same folder and are not book engravings, so they are out.

  • One plate per printed figure. Where an automatic crop and a later hand crop cover

the same printed figure, the hand crop wins, because it was cut after the page was opened at 400 to 500 ppi and its notes name the scan it was read from.

  • A per-chapter cap. Without it the gallery would be chapter III, which is dense

with diagrams, and the rest of the volume would be a footnote.

Then the captions. For each surviving plate the tool re-derives the ink band the extractor cut, at the same 300 ppi and in the same order, and reads the text lines in the strip of print between that band and the next figure on the page. A line counts as a caption only if it is nothing but a caption: a body sentence that happens to begin with a figure word is not one. The book sets its captions in small caps and the scan's text layer mangles them, so the line the print sets as FIG. 1. arrives as Fie. l., and the line the print sets as FIGS. 45, 46 and 47. arrives as Fms. 45, 46 and 47.; the reader normalizes only the letter-for-digit confusions this scan actually makes, and the selection record keeps each line exactly as the layer gave it, so every normalization can be checked against the print it came from. Where the strip under a plate holds no caption line at all, the plate is left out rather than guessed at.

What that produced, stated as counts so it can be re-run and argued with: of the 223 catalogued crops, 4 are not book figures at all, 129 fail the rules above (72 because their printed figure number was never read correctly, 29 because they are C-grade, 15 because no caption line sits under them, 7 because their own QC note leaves the number unsettled, 5 because the QC pass marked them keep-tight or drop, 1 because the caption line is there with its number unreadable), 90 pass, 5 of those are second crops of a figure already in the pool, and the 85 unique printed figures are capped to the 72 on this page. They cover 30 chapters across all four parts of the volume: 24 in Part I, 23 in Part II, 21 in Part III, 4 in the Appendix. 66 are graded A and 6 are graded B. 19 are hand crops cut against the print at 400 to 500 ppi. 17 carry a figure number different from the one their file name claims, because the caption under the plate said something else. 21 captions name more than one figure, because the extractor's band runs across two or three figures the page captions separately, and a caption that quietly drops the other two is not describing the plate it is under.

The full record, plate by plate and rejection by rejection, is new_content/1894-series/plates/selection.json, and books/tools/plates_gallery.py writes it. Re-run the command and you get this page or you do not, which is the whole point of writing it down.

Part I: Polyphase Currents

Plates the volume prints in this part, in printed page order.

Chapter III: The Tesla Rotating Magnetic Field

Chapter III, beginning at printed p. 9.

1894 engraving, figs. 1 and 1a, printed p. 11: Two diagrams side by side: an armature drum with coils C between two field-magnet pole pieces, and a circular development diagram of four coil segments C/C1 on an N-S axis

Figs. 1 and 1a · printed p. 11 · Ch. III · engraving

Two diagrams side by side: an armature drum with coils C between two field-magnet pole pieces, and a circular development diagram of four coil segments C/C1 on an N-S axis

1894 engraving, fig. 2a, printed p. 11: Same two-diagram pair with the armature turned about 45 degrees; coil segments shown skewed in the circular diagram

Fig. 2a · printed p. 11 · Ch. III · engraving

Same two-diagram pair with the armature turned about 45 degrees; coil segments shown skewed in the circular diagram

1894 engraving, figs. 3 and 3a, printed p. 12: Armature drum between pole pieces plus circular coil-segment diagram, armature advanced three-eighths of a turn

Figs. 3 and 3a · printed p. 12 · Ch. III · engraving

Armature drum between pole pieces plus circular coil-segment diagram, armature advanced three-eighths of a turn

1894 engraving, figs. 4 and 4a, printed p. 12: Same Fig.4 pair at a further rotation

Figs. 4 and 4a · printed p. 12 · Ch. III · engraving

Same Fig.4 pair at a further rotation

1894 engraving, figs. 7 and 7a, printed p. 14: Armature-drum and circular coil diagrams, another angular position

Figs. 7 and 7a · printed p. 14 · Ch. III · engraving

Armature-drum and circular coil diagrams, another angular position

1894 engraving, fig. 8a, printed p. 15: Armature-drum and circular coil diagrams, another angular position

Fig. 8a · printed p. 15 · Ch. III · engraving

Armature-drum and circular coil diagrams, another angular position

Chapter IV: Modifications and Expansions of the Tesla Polyphase Systems

Chapter IV, beginning at printed p. 26.

1894 engraving, fig. 24, printed p. 27: Polyphase generator and motor linked through transformers to three lamp/meter sets - full wiring diagram

Fig. 24 · printed p. 27 · Ch. IV · engraving

Polyphase generator and motor linked through transformers to three lamp/meter sets - full wiring diagram

1894 engraving, fig. 23, printed p. 28: Alternator with transformer and three meter/lamp branches in a wiring diagram

Fig. 23 · printed p. 28 · Ch. IV · engraving

Alternator with transformer and three meter/lamp branches in a wiring diagram

Chapter V: Utilizing Familiar Types of Generators of the Continuous Current Type

Chapter V, beginning at printed p. 31.

1894 engraving, fig. 25, printed p. 32: Disc-type alternator with radial conductors feeding a switchboard and a second machine

Fig. 25 · printed p. 32 · Ch. V · engraving

Disc-type alternator with radial conductors feeding a switchboard and a second machine

1894 engraving, figs. 27 and 26, printed p. 34: Segmented ring armature with switch/commutator blocks and connecting leads

Figs. 27 and 26 · printed p. 34 · Ch. V · engraving

Segmented ring armature with switch/commutator blocks and connecting leads

Chapter VI: Method of Obtaining Desired Speed of Motor or Generator

Chapter VI, beginning at printed p. 36.

1894 engraving, figs. 28 and 29, printed p. 37: Two polyphase machines coupled by line leads, one with a segmented ring

Figs. 28 and 29 · printed p. 37 · Ch. VI · engraving

Two polyphase machines coupled by line leads, one with a segmented ring

1894 engraving, fig. 30, printed p. 38: Two segmented-ring machines (a generator and a motor) coupled through a small transformer/switch block

Fig. 30 · printed p. 38 · Ch. VI · engraving

Two segmented-ring machines (a generator and a motor) coupled through a small transformer/switch block

1894 engraving, fig. 33, printed p. 42: Wiring diagram: battery at top, small alternator at left, large segmented-ring machine at bottom, with meters

Fig. 33 · printed p. 42 · Ch. VI · engraving

Wiring diagram: battery at top, small alternator at left, large segmented-ring machine at bottom, with meters

Chapter VII: Regulator for Rotary Current Motors

Chapter VII, beginning at printed p. 45.

1894 engraving, fig. 36, printed p. 47: Three apparatus blocks in a row: induction coil, switch panel, and a small machine with leads

Fig. 36 · printed p. 47 · Ch. VII · engraving

Three apparatus blocks in a row: induction coil, switch panel, and a small machine with leads

Chapter X: Motor With Current Lag Artificially Secured

Chapter X, beginning at printed p. 58.

1894 engraving, figs. 45, 46 and 47, printed p. 60: Circuit diagram, two parallel coil branches into a coil pair, Line terminals

Figs. 45, 46 and 47 · printed p. 60 · Ch. X · engraving

Circuit diagram, two parallel coil branches into a coil pair, Line terminals

1894 engraving, fig. 48, printed p. 61: Large machine on a base: circular segmented ring with windings and terminal posts

Fig. 48 · printed p. 61 · Ch. X · engraving

Large machine on a base: circular segmented ring with windings and terminal posts

Chapter XI: Another Method of Transformation From a Torque to a Synchronizing Motor

Chapter XI, beginning at printed p. 62.

1894 engraving, fig. 52, printed p. 64: Ring with eight segment coils at left and a six-pointed star-shaped rotor/armature at right

Fig. 52 · printed p. 64 · Ch. XI · engraving

Ring with eight segment coils at left and a six-pointed star-shaped rotor/armature at right

1894 engraving, fig. 53, printed p. 65: Circuit diagram with coil pairs at left connected to a six-pointed star rotor at right

Fig. 53 · printed p. 65 · Ch. XI · engraving

Circuit diagram with coil pairs at left connected to a six-pointed star rotor at right

Chapter XVI: Motor With Equal Magnetic Energies in Field and Armature

Chapter XVI, beginning at printed p. 81.

1894 engraving, fig. 67, printed p. 81: Machine on a base: ring frame with four coil groups and a shaded disc armature

Fig. 67 · printed p. 81 · Ch. XVI · engraving

Machine on a base: ring frame with four coil groups and a shaded disc armature

Chapter XVII: Motors With Coinciding Maxima of Magnetic Effect in Armature and Field

Chapter XVII, beginning at printed p. 83.

1894 engraving, fig. 71, printed p. 86: Ring machine with segment coils at left, and a four-block collector/commutator section on a shaft at right

Fig. 71 · printed p. 86 · Ch. XVII · engraving

Ring machine with segment coils at left, and a four-block collector/commutator section on a shaft at right

Chapter XVIII: Motor Based on the Difference of Phase in the Magnetization of the Inner and Outer Parts of an Iron Core

Chapter XVIII, beginning at printed p. 88.

1894 engraving, fig. 74, printed p. 90: Vertical machine in section: drum armature on a shaft between two bearing/brush blocks

Fig. 74 · printed p. 90 · Ch. XVIII · engraving

Vertical machine in section: drum armature on a shaft between two bearing/brush blocks

Chapter XX: Combinations of Synchronizing Motor and Torque Motor

Chapter XX, beginning at printed p. 95.

1894 engraving, figs. 78 and 79, printed p. 97: Two segmented-ring machines side by side on bases, with connecting leads

Figs. 78 and 79 · printed p. 97 · Ch. XX · engraving

Two segmented-ring machines side by side on bases, with connecting leads

Chapter XXII: Motor With Condenser in One of the Field Circuits

Chapter XXII, beginning at printed p. 106.

1894 engraving, fig. 91, printed p. 107: Large machine on a base: ring frame with segment coils and shaded poles, small instrument mounted above

Fig. 91 · printed p. 107 · Ch. XXII · engraving

Large machine on a base: ring frame with segment coils and shaded poles, small instrument mounted above

Chapter XXIV: A Constant Current Transformer With Magnetic Shield Between Coils of Primary and Secondary

Chapter XXIV, beginning at printed p. 113.

1894 engraving, fig. 95, printed p. 114: Two long mesh-screened rectangles with taps and leads - a modified transformer form

Fig. 95 · printed p. 114 · Ch. XXIV · engraving

Two long mesh-screened rectangles with taps and leads - a modified transformer form

Part II: The Tesla Effects With High Frequency and High Potential Currents

Plates the volume prints in this part, in printed page order.

Chapter XXVI: The New York Lecture

Chapter XXVI, beginning at printed p. 145.

1894 photograph, fig. 97, printed p. 153: Of a large disc machine on an X-frame stand, bolted to a plank base

Fig. 97 · printed p. 153 · Ch. XXVI · photograph

Of a large disc machine on an X-frame stand, bolted to a plank base

1894 photograph, figs. 116 and 117, printed p. 179: Two photographs of exhausted glass lamps with their printed captions FIG. 116. and FIG. 117.: left a globe with a refractory filament body, right a larger globe showing a refractory block clamped between two leads

Figs. 116 and 117 · printed p. 179 · Ch. XXVI · photograph

Two photographs of exhausted glass lamps with their printed captions FIG. 116. and FIG. 117.: left a globe with a refractory filament body, right a larger globe showing a refractory block clamped between two leads

1894 photograph, fig. 124, printed p. 185: A sheet-wound induction coil on two posts at left with a hand near one terminal, an exhausted lamp at centre surrounded by a dark outside condenser coating, a square insulated metal plate at right, with the printed FIG. 124. caption

Fig. 124 · printed p. 185 · Ch. XXVI · photograph

A sheet-wound induction coil on two posts at left with a hand near one terminal, an exhausted lamp at centre surrounded by a dark outside condenser coating, a square insulated metal plate at right, with the printed FIG. 124. caption

1894 photograph, fig. 125, printed p. 188: Two metal sheets drawn in perspective one above the other, dark discharge about the edges of both and a dark column between them, two exhausted tubes glowing in that space, and at the left the connections drawn schematically (source symbol at the bottom, a small rectangular device, two coupled coils as spirals, one lead from each terminal to a sheet); printed FIG. 125. caption at the right

Fig. 125 · printed p. 188 · Ch. XXVI · photograph

Two metal sheets drawn in perspective one above the other, dark discharge about the edges of both and a dark column between them, two exhausted tubes glowing in that space, and at the left the connections drawn schematically (source symbol at the bottom, a small rectangular device, two coupled coils as spirals, one lead from each terminal to a sheet); printed FIG. 125. caption at the right

1894 engraving, fig. 126, printed p. 192: An induction coil at left driving a condenser across a spark gap, the discharge circuit running to five incandescent lamps in parallel between two conductors, with the printed FIG. 126. caption

Fig. 126 · printed p. 192 · Ch. XXVI · engraving

An induction coil at left driving a condenser across a spark gap, the discharge circuit running to five incandescent lamps in parallel between two conductors, with the printed FIG. 126. caption

1894 engraving, fig. 127, printed p. 193: A coil connected to a tube and a receiving coil

Fig. 127 · printed p. 193 · Ch. XXVI · engraving

A coil connected to a tube and a receiving coil

Chapter XXVII: The London Lecture

Chapter XXVII, beginning at printed p. 198.

1894 photograph, figs. 144 and 145, printed p. 228: Two photographs, Figs. 144 and 145: exhausted lamp globes above their screw bases on dark grounds, left with luminous rays radiating across the whole globe from its centre, right with the rays gathered into a fan at one side

Figs. 144 and 145 · printed p. 228 · Ch. XXVII · photograph

Two photographs, Figs. 144 and 145: exhausted lamp globes above their screw bases on dark grounds, left with luminous rays radiating across the whole globe from its centre, right with the rays gathered into a fan at one side

1894 photograph, fig. 146, printed p. 234: A coil wound on a long horizontal iron core on two stands, a disc on a pillar at the left end, a transformer in a case at upper left, a square metal plate suspended at the right, with the printed FIG. 146. caption and the plate labels TRANSFORMER / ROTATING DISC / IRON CORE / PLATE SUSPENDED

Fig. 146 · printed p. 234 · Ch. XXVII · photograph

A coil wound on a long horizontal iron core on two stands, a disc on a pillar at the left end, a transformer in a case at upper left, a square metal plate suspended at the right, with the printed FIG. 146. caption and the plate labels TRANSFORMER / ROTATING DISC / IRON CORE / PLATE SUSPENDED

1894 photograph, figs. 163 and 164, printed p. 288: Fig. 163 (left) and Fig. 164 (right), each a tall sealed tube with a stem and coatings at its lower end

Figs. 163 and 164 · printed p. 288 · Ch. XXVII · photograph

Fig. 163 (left) and Fig. 164 (right), each a tall sealed tube with a stem and coatings at its lower end

Chapter XXVIII: The Philadelphia and St. Louis Lecture

Chapter XXVIII, beginning at printed p. 294.

1894 engraving, figs. 168a and 168b, printed p. 313: Two views of a small device, plan and section (labelled 168a/168b in the book)

Figs. 168a and 168b · printed p. 313 · Ch. XXVIII · engraving

Two views of a small device, plan and section (labelled 168a/168b in the book)

1894 engraving, figs. 170a and 170b, printed p. 321: Two cylindrical coils with spark streams between them

Figs. 170a and 170b · printed p. 321 · Ch. XXVIII · engraving

Two cylindrical coils with spark streams between them

1894 engraving, fig. 175, printed p. 328: Two vertical plates with a coil and a break device between them

Fig. 175 · printed p. 328 · Ch. XXVIII · engraving

Two vertical plates with a coil and a break device between them

1894 engraving, fig. 176, printed p. 329: A plate, a glowing coil and a second plate in circuit

Fig. 176 · printed p. 329 · Ch. XXVIII · engraving

A plate, a glowing coil and a second plate in circuit

1894 engraving, fig. 180, printed p. 335: Four line diagrams, Fig. 180 I. to IV.: each hangs from one line L drawn across the top, with primaries, secondaries, a condenser C, motors M1 to M4, and in plan II an iron core with coil c and a disc d marked with a turning arrow

Fig. 180 · printed p. 335 · Ch. XXVIII · engraving

Four line diagrams, Fig. 180 I. to IV.: each hangs from one line L drawn across the top, with primaries, secondaries, a condenser C, motors M1 to M4, and in plan II an iron core with coil c and a disc d marked with a turning arrow

1894 engraving, fig. 184, printed p. 344: Line diagram, Fig. 184: an alternator marked G feeding two line wires L and L1 across the plate; plan II, a coil in many sections tapped at an intermediate point with a phosphorescence lamp B at its free end; plan I, a coil C1 with a brush of discharge at one end, led through condenser plates c and c1 to a large rectangular plate P1

Fig. 184 · printed p. 344 · Ch. XXVIII · engraving

Line diagram, Fig. 184: an alternator marked G feeding two line wires L and L1 across the plate; plan II, a coil in many sections tapped at an intermediate point with a phosphorescence lamp B at its free end; plan I, a coil C1 with a brush of discharge at one end, led through condenser plates c and c1 to a large rectangular plate P1

Chapter XXIX: Tesla Alternating Current Generators for High Frequency

Chapter XXIX, beginning at printed p. 374.

1894 engraving, fig. 205, printed p. 378: Plan view of a machine: two square coil groups on a frame with a shaft and a flywheel

Fig. 205 · printed p. 378 · Ch. XXIX · engraving

Plan view of a machine: two square coil groups on a frame with a shaft and a flywheel

1894 engraving, fig. 206, printed p. 379: Section through a machine: hatched pole pieces, shaft, and terminal posts

Fig. 206 · printed p. 379 · Ch. XXIX · engraving

Section through a machine: hatched pole pieces, shaft, and terminal posts

Chapter XXX: Alternate Current Electrostatic Induction Apparatus

Chapter XXX, beginning at printed p. 392.

1894 engraving, fig. 208, printed p. 392: A ring marked A lined on the inside with two sets of tin-foil coatings marked a and b, and inside it a cylinder marked B carrying coatings marked a1 and b1, the two sets led out to two ring terminals marked T with + and - signs; dashed field lines drawn through both

Fig. 208 · printed p. 392 · Ch. XXX · engraving

A ring marked A lined on the inside with two sets of tin-foil coatings marked a and b, and inside it a cylinder marked B carrying coatings marked a1 and b1, the two sets led out to two ring terminals marked T with + and - signs; dashed field lines drawn through both

1894 engraving, fig. 209, printed p. 393: A circular plate carrying two sets of coatings marked a and b cut as six lobed sectors, a shaft cross-section at the centre, and two leads run out to two ring terminals at the lower right

Fig. 209 · printed p. 393 · Ch. XXX · engraving

A circular plate carrying two sets of coatings marked a and b cut as six lobed sectors, a shaft cross-section at the centre, and two leads run out to two ring terminals at the lower right

Chapter XXXII: Electric Discharge in Vacuum Tubes

Chapter XXXII, beginning at printed p. 396.

1894 engraving, fig. 210, printed p. 397: An incandescent lamp bulb drawn in section with a glass tube sealed at one end standing inside it and a heavy shaded cylinder inside that tube, two leads bent at right angles at the foot, fine curved lines in the space between tube and bulb, a small separate hatched detail at the lower right

Fig. 210 · printed p. 397 · Ch. XXXII · engraving

An incandescent lamp bulb drawn in section with a glass tube sealed at one end standing inside it and a heavy shaded cylinder inside that tube, two leads bent at right angles at the foot, fine curved lines in the space between tube and bulb, a small separate hatched detail at the lower right

1894 engraving, fig. 215, printed p. 400: A spiral coil wound round a cylinder with a vacuum lamp suspended inside, leads P and P1

Fig. 215 · printed p. 400 · Ch. XXXII · engraving

A spiral coil wound round a cylinder with a vacuum lamp suspended inside, leads P and P1

1894 engraving, fig. 218, printed p. 403: A bell-jar on a flat base, an exhausted bulb inside it with its long neck through a stopper at the top and three leads led down into it, a spiral of four turns of wire around the body of the bulb with both ends led up out of the jar

Fig. 218 · printed p. 403 · Ch. XXXII · engraving

A bell-jar on a flat base, an exhausted bulb inside it with its long neck through a stopper at the top and three leads led down into it, a spiral of four turns of wire around the body of the bulb with both ends led up out of the jar

1894 engraving, figs. 218 and 219, printed p. 403: A glass flask containing a spiral coil with multiple leads, beside a small two-bulb device

Figs. 218 and 219 · printed p. 403 · Ch. XXXII · engraving

A glass flask containing a spiral coil with multiple leads, beside a small two-bulb device

Part III: Miscellaneous Inventions and Writings

Plates the volume prints in this part, in printed page order.

Chapter XXXIII: Method of Obtaining Direct From Alternating Currents

Chapter XXXIII, beginning at printed p. 409.

1894 engraving, fig. 220, printed p. 410: One circuit diagram - a rectangular box marked A low in the centre, two conductors marked B leading out of it and turning up at the sides of the plate, dividing at a point marked Y at the left and rejoining at a point marked X at the right, an upper branch marked C carrying a round cell symbol with one long and one short bar marked E, a lower branch marked D carrying the same symbol marked F, and three small dark diamond symbols set at intervals along each branch

Fig. 220 · printed p. 410 · Ch. XXXIII · engraving

One circuit diagram - a rectangular box marked A low in the centre, two conductors marked B leading out of it and turning up at the sides of the plate, dividing at a point marked Y at the left and rejoining at a point marked X at the right, an upper branch marked C carrying a round cell symbol with one long and one short bar marked E, a lower branch marked D carrying the same symbol marked F, and three small dark diamond symbols set at intervals along each branch

1894 engraving, fig. 221, printed p. 411: Two machine sections with meters in a circuit

Fig. 221 · printed p. 411 · Ch. XXXIII · engraving

Two machine sections with meters in a circuit

1894 engraving, fig. 222, printed p. 412: Four machine units arranged around a central disc - a diagrammatic polyphase arrangement

Fig. 222 · printed p. 412 · Ch. XXXIII · engraving

Four machine units arranged around a central disc - a diagrammatic polyphase arrangement

1894 engraving, fig. 223, printed p. 413: Four field coils with two armatures in a circuit

Fig. 223 · printed p. 413 · Ch. XXXIII · engraving

Four field coils with two armatures in a circuit

1894 engraving, fig. 224, printed p. 414: Circuit with four magnet units and two armatures, labelled as a distinct type of connection

Fig. 224 · printed p. 414 · Ch. XXXIII · engraving

Circuit with four magnet units and two armatures, labelled as a distinct type of connection

Chapter XXXIV: Condensers With Plates in Oil

Chapter XXXIV, beginning at printed p. 418.

1894 engraving, fig. 227, printed p. 418: A rectangular can shown in section with its walls hatched, a stack of horizontal plates standing inside near each end marked B and c, three dark vertical strips between the two stacks marked F, the whole interior filled with a stippled space marked G, a terminal led out through the middle of each short wall marked D and E, the case marked A

Fig. 227 · printed p. 418 · Ch. XXXIV · engraving

A rectangular can shown in section with its walls hatched, a stack of horizontal plates standing inside near each end marked B and c, three dark vertical strips between the two stacks marked F, the whole interior filled with a stippled space marked G, a terminal led out through the middle of each short wall marked D and E, the case marked A

Chapter XXXV: Electrolytic Registering Meter

Chapter XXXV, beginning at printed p. 420.

1894 engraving, fig. 229, printed p. 421: A long spiral-wound tube with tapped terminals down one side and a galvanometer

Fig. 229 · printed p. 421 · Ch. XXXV · engraving

A long spiral-wound tube with tapped terminals down one side and a galvanometer

1894 engraving, fig. 280, printed p. 422: A long tube with two coil ends and a row of tapped contacts

Fig. 280 · printed p. 422 · Ch. XXXV · engraving

A long tube with two coil ends and a row of tapped contacts

Chapter XXXVI: Thermo-Magnetic Motors and Pyro-Magnetic Generators

Chapter XXXVI, beginning at printed p. 424.

1894 engraving, figs. 235 and 234, printed p. 426: Three views of a frame machine with a helix and armature, plus a small motor at centre

Figs. 235 and 234 · printed p. 426 · Ch. XXXVI · engraving

Three views of a frame machine with a helix and armature, plus a small motor at centre

1894 engraving, fig. 242, printed p. 430: A long horizontal bundle of parallel tubes in section spanning the width of the plate, wound at two places with coils of many turns marked F and E', those two coils led up to two small round instruments marked r and r'; the middle of the bundle passes up through a column standing in a rectangular firebox marked D with a fire drawn under it and a door with a handle at its foot, and above the firebox the column branches into two vertical vessels partly filled with liquid with a wide flue rising between them; pipes marked H and G run from near the ends of the tube bundle up and over to those vessels, one of them with a valve in it; a spring loaded fitting marked V S J at the left end of the bundle, and the whole machine standing on a flat base marked A

Fig. 242 · printed p. 430 · Ch. XXXVI · engraving

A long horizontal bundle of parallel tubes in section spanning the width of the plate, wound at two places with coils of many turns marked F and E', those two coils led up to two small round instruments marked r and r'; the middle of the bundle passes up through a column standing in a rectangular firebox marked D with a fire drawn under it and a door with a handle at its foot, and above the firebox the column branches into two vertical vessels partly filled with liquid with a wide flue rising between them; pipes marked H and G run from near the ends of the tube bundle up and over to those vessels, one of them with a valve in it; a spring loaded fitting marked V S J at the left end of the bundle, and the whole machine standing on a flat base marked A

Chapter XXXVII: Anti-Sparking Dynamo Brush and Commutator

Chapter XXXVII, beginning at printed p. 432.

1894 engraving, figs. 247 and 246, printed p. 434: A machine section with a commutator, beside a circular diagram of four quadrant segments

Figs. 247 and 246 · printed p. 434 · Ch. XXXVII · engraving

A machine section with a commutator, beside a circular diagram of four quadrant segments

1894 engraving, figs. 248, 249 and 250, printed p. 435: A segmented commutator disc in quadrant shading, with two small detail blocks

Figs. 248, 249 and 250 · printed p. 435 · Ch. XXXVII · engraving

A segmented commutator disc in quadrant shading, with two small detail blocks

Chapter XXXVIII: Auxiliary Brush Regulation of Direct Current Dynamos

Chapter XXXVIII, beginning at printed p. 438.

1894 engraving, fig. 253, printed p. 439: A coil above a rotating disc with contact points, feeding a row of lamps

Fig. 253 · printed p. 439 · Ch. XXXVIII · engraving

A coil above a rotating disc with contact points, feeding a row of lamps

1894 engraving, fig. 255, printed p. 441: Coil-and-disc interrupter with a row of lamps

Fig. 255 · printed p. 441 · Ch. XXXVIII · engraving

Coil-and-disc interrupter with a row of lamps

1894 engraving, fig. 256, printed p. 442: Two views of a mechanical brush/linkage mechanism with a battery

Fig. 256 · printed p. 442 · Ch. XXXVIII · engraving

Two views of a mechanical brush/linkage mechanism with a battery

1894 engraving, fig. 266, printed p. 446: Two views of a vertical machine with a star-shaped rotor and a base

Fig. 266 · printed p. 446 · Ch. XXXVIII · engraving

Two views of a vertical machine with a star-shaped rotor and a base

Chapter XXXIX: Improvement in Dynamo and Motor Construction

Chapter XXXIX, beginning at printed p. 448.

1894 engraving, fig. 268, printed p. 449: Machine frame with two large curved pole pieces and a central armature on a plank base

Fig. 268 · printed p. 449 · Ch. XXXIX · engraving

Machine frame with two large curved pole pieces and a central armature on a plank base

Chapter XL: Tesla Direct Current Arc Lighting System

Chapter XL, beginning at printed p. 451.

1894 engraving, fig. 271, printed p. 452: A machine with a row of pointed contacts along a shaft and a flywheel

Fig. 271 · printed p. 452 · Ch. XL · engraving

A machine with a row of pointed contacts along a shaft and a flywheel

1894 engraving, figs. 275 and 276, printed p. 455: A segmented ring diagram beside a machine section with a piston-like element

Figs. 275 and 276 · printed p. 455 · Ch. XL · engraving

A segmented ring diagram beside a machine section with a piston-like element

Chapter XLI: Improvement in Unipolar Generators

Chapter XLI, beginning at printed p. 465.

1894 engraving, figs. 290 and 291, printed p. 466: Side view, partly in section, of a machine with two flywheels on a base

Figs. 290 and 291 · printed p. 466 · Ch. XLI · engraving

Side view, partly in section, of a machine with two flywheels on a base

1894 engraving, figs. 295 and 296, printed p. 473: Two ring diagrams with spirals and a radial conductor

Figs. 295 and 296 · printed p. 473 · Ch. XLI · engraving

Two ring diagrams with spirals and a radial conductor

Part IV: Appendix: Early Phase Motors and the Tesla Oscillators

Plates the volume prints in this part, in printed page order.

Chapter XLII: Mr. Tesla's Personal Exhibit at the World's Fair

Chapter XLII, beginning at printed p. 477.

1894 engraving, fig. 297, printed p. 478: Long table of motors, rings and coils at the World's Fair exhibit, railing in front, 'Electrical Engineer' credit lower right

Fig. 297 · printed p. 478 · Ch. XLII · engraving

Long table of motors, rings and coils at the World's Fair exhibit, railing in front, 'Electrical Engineer' credit lower right

1894 engraving, fig. 298, printed p. 480: Laminated-iron ring field with an armature on cross bolts, on a plank base

Fig. 298 · printed p. 480 · Ch. XLII · engraving

Laminated-iron ring field with an armature on cross bolts, on a plank base

1894 engraving, figs. 300 to 308, printed p. 482: Nine armature engravings with their printed captions, Fig. 300 to Fig. 308

Figs. 300 to 308 · printed p. 482 · Ch. XLII · engraving

Nine armature engravings with their printed captions, Fig. 300 to Fig. 308

Chapter XLIII: The Tesla Mechanical and Electrical Oscillators

Chapter XLIII, beginning at printed p. 486.

1894 engraving, fig. 313, printed p. 491: Of Tesla's mechanical oscillator: a piston on a shaft in a cylinder, inside a magnetic frame with energising coils

Fig. 313 · printed p. 491 · Ch. XLIII · engraving

Of Tesla's mechanical oscillator: a piston on a shaft in a cylinder, inside a magnetic frame with energising coils

The Download

The ZIP is the same 72 plates at up to 1200 pixels on the long edge, as PNG, with a README that lists each file against its figure number, printed page and chapter and repeats the page rule and the licence: tesla-1894-plates.zip, about 10 MB.

If you want to link to something rather than download it, this page is the thing to link to: it is the set, the method and the citations in one place, and the credit line above is the one we would like back. The hub of this series is The 1894 File, and it links here. The pages this series writes about the same volume are on the articles index, including the World's Fair exhibit this gallery's Appendix plates came from, the 1891 lecture that explains the diagrams in Part II, the glowing tubes chapter, which reads the four different texts inside one chapter, and what Tesla actually wrote about free energy. The counting method behind the claims in those pages, the two indexes a count can be taken over, and the printed page of every hit are on Tesla 1894 Word Search.

Sources

  • The Inventions, Researches and Writings of Nikola Tesla, ed. Thomas Commerford Martin. New York: D. Van Nostrand, 1894 (entered 1893). Scan: archive.org item inventionsresear00martiala. Public domain.
  • The selection record: new_content/1894-series/plates/selection.json. It carries every plate on this page with its printed page, its printed figure numbers, its chapter, its quality grade, the manifest row it came from, and how its caption was read, plus every row the rules rejected and the reason. books/tools/plates_gallery.py --select writes it, and re-running that command reproduces this page
  • The QC pass those rows come from: manifest_qc.csv, in the website/assets/tesla1894/ folder, 223 catalogued crops, each with a verdict, a subject line written while looking at the crop, an A/B/C quality grade, and whether the aspect and the printed figure number were checked. That file is the §6.2 pass, not this task's work, and this page only reads it
  • The chapter map: books/extracted/chapters-1894.json, read off the book's own printed contents pages (the scans the running heads are not), which is what lets a plate be named by chapter as well as by page
  • The caption reading: books/tools/extract_figures.py re-derives the extractor's own ink band at 300 ppi, and the caption is taken from the strip of print between that band and the next figure on the page, which is the only positional way to read a caption when the text layer of the same page also mentions figures inside body paragraphs
  • The three plates shown in this article's own text, at printed pp. 378, 392 and 478, are three of the 72 on the grid below and carry the same captions here as there, so nothing is said twice in two different ways
  • The word 'accompanying', which the scan prints as 'aecompaning' on printed p. 375 and as 'accompanying' elsewhere: the quotes on this page are taken from the pages where the scan is clean, and every one of them was re-grepped from books/extracted/tesla-1894-plain.txt and pinned to its printed page before it was written here
  • Pages of the 1894 edition used here: p. 14, p. 378, p. 379, p. 392, p. 393, p. 478, p. 482, p. 483
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