Skip to content

Archaic Legal Glossary & Citations

“Letters Patent”14th–20th Century
19th-C Meaning:

Open public letters from a monarch or government (literae patentes) granting monopoly rights.

Modern Engineering Decoded:Issued USPTO utility or design patent publication.
Historical note: Contrasted with 'letters close' (private sealed royal correspondence).
“In testimony whereof”19th Century
19th-C Meaning:

Formal concluding legal formula affirming under oath the execution of the instrument.

Modern Engineering Decoded:Inventor and witness digital/physical signatures.
Historical note: Required two witness attestations in 19th-century USPTO filing procedure.
“Aeroplane”Early 20th Century (Wright era)
19th-C Meaning:

A flat or cambered lifting aerofoil surface supported dynamically by air pressure.

Modern Engineering Decoded:Wing / Airfoil lifting surface (later evolved to mean the entire motorized aircraft).
Historical note: The Wrights used 'aeroplane' to denote the individual fabric-covered wings.
“Undulating Current”19th Century (Bell era)
19th-C Meaning:

An electric current whose magnitude varies continuously and periodically without interruption.

Modern Engineering Decoded:Continuous analog AC or audio-frequency electrical waveform.
Historical note: Bell's central legal weapon against telegraph companies who relied on pulsed DC make-and-break circuits.
“Subdivision of the Electric Light”1870s–1880s (Edison era)
19th-C Meaning:

The problem of operating numerous small domestic lamps off a single electrical generator.

Modern Engineering Decoded:Parallel circuit wiring of high-resistance incandescent electrical loads.
Historical note: Pundits claimed it was physically impossible until Edison increased filament resistance to 100 ohms.
“Optically Anisotropic Solution”1960s (Kwolek era)
19th-C Meaning:

A liquid solution that exhibits direction-dependent refractive indices due to molecular alignment.

Modern Engineering Decoded:Liquid crystalline nematic phase polymer dope.
Historical note: Technicians initially tried to throw out Kwolek's cloudy solution thinking it was contaminated.
“Unitary Body of Semiconductor Material”1950s–1960s (Noyce era)
19th-C Meaning:

A single continuous crystal structure of silicon or germanium.

Modern Engineering Decoded:Monolithic single-crystal silicon die / integrated circuit wafer.
Historical note: Differentiated Noyce's monolithic planar circuit from Jack Kilby's hybrid flying-wire prototype.
“Peculiar and Novel Construction”19th Century
19th-C Meaning:

A distinctive, patentable structural arrangement not found in prior art.

Modern Engineering Decoded:Novel and non-obvious mechanical embodiment under 35 U.S.C. § 103.
Historical note: Standard 19th-century legal terminology establishing novelty.

Museum Broadside & Archival Print Edition

Authentic archival layout formatted for framing, study, and high-resolution printing

Paper:
Theme:
The United States Patent & Trademark Archive

Historical Specification & Engineering Broadside

Curated, Verified & Restored by Classic Patents (classic-patents.com)
CAMERARemovable Film Holder and Spring-Driven Cylindrical Shutter
US 388,850Class: Not stated on the pinned facsimile.
Inventor(s):George Eastman
Origin / Location:Rochester, Monroe County, New York
Grant & Filing:Filed March 30, 1888 · Granted September 4, 1888

I. Historical Context & Grant Summary

US 388,850 describes a tubular camera case with a removable rear roller-holder for prepared film and a removable, light-tight front lens-and-shutter module. Its 41 claims cover the paired-aperture cylindrical shutter, its spring-and-ratchet drive and release controls, the sectional front block, and the rear film carrier.

II. Core Mechanism & Scientific Principles

The grant solves a mechanical packaging problem: keep prepared film dark inside a portable box, yet let the user load the film holder, wind the shutter spring, release an exposure, advance film, and remove the modules without reopening an uncontrolled light path.

Physical Operation:The optical path runs through a front aperture and lens. A hollow cylinder around the lens has matching openings on opposite sides; opaque cylinder wall blocks the path at rest, and a spring-driven half-turn moves the openings across the lens. A rear roller-holder holds the film on supply and winding spools and seals the rear of the tubular case.
Governing Formulation:
Light exclusion:\Phi_{\text{stray}} \approx 0 \implies E_{\text{film}} = \frac{\pi L}{4 N^2}
Rotational energy storage:U = \frac{1}{2} k \theta^2 \quad \text{and} \quad \tau = k \theta

III. The Granted Legal Monopoly (Key Claims)

Claim 1 (Independent)Tubular case with two removable end modules

Claim 1 protects the complete modular camera: a tubular case is closed at the rear by the detachable film-holder, at the front by a block or end piece, and the removable lens-support and shutter sit in that front chamber. The legal combination is the three-part light-tight body, not merely any one component.

Claim 2 (Independent)Coincident-aperture front chamber

Claim 2 narrows the front assembly to a partition or block that closes the case, forms a chamber with coincident openings, and holds a fixed lens-support with a rotary shutter in fixed relation. It protects the aligned optical passage and the supported rotating mechanism together.

Claim 3 (Independent)Sectional diaphragm and cap

Claim 3 specifies the sectional front closure: a fixed diaphragm, a cooperating apertured cap, an internal chamber between them, a lens between their apertures, and a shutter on its support. This is the detailed two-piece front block that admits light only through the controlled path.

IV. Mechanical Organ Breakdown

Front block and chamberTerm: “Block or diaphragm” → Light-tight front bulkhead

A sectional front block receives the removable lens-and-shutter unit while excluding stray light.

Cylindrical shutterTerm: “Cylindrical shutter” → Rotary barrel shutter

A hollow cylinder with coincident openings surrounds the lens.

Spring drive and releaseTerm: “Motor mechanism” → Spring-powered shutter drive

An external cord winds a spring through a ratchet; a push-pin and latch release and arrest motion.

Roller-holderTerm: “Roller-holder” → Removable roll-film carrier

The rear assembly carries prepared film, guides it over a platen, and winds it forward.

CLASSIC PATENTS DIGITAL ARCHIVE • PERMANENT EXHIBIT ID: us-388850-eastman-kodak
classic-patents.com/patents/us-388850-eastman-kodak
Original USPTO PDF
Classic Patents/US 388,850
Gilded Age & Grid (1870–1900)Photographic Optics and Mechanisms

Eastman Light-Tight Roll-Film Camera

US 388,850

Removable Film Holder and Spring-Driven Cylindrical Shutter

Inventor(s)George Eastman
Grant DateSeptember 4, 1888
Filing DateMarch 30, 1888
LocationRochester, Monroe County, New York
US 388,850 describes a tubular camera case with a removable rear roller-holder for prepared film and a removable, light-tight front lens-and-shutter module. Its 41 claims cover the paired-aperture cylindrical shutter, its spring-and-ratchet drive and release controls, the sectional front block, and the rear film carrier.
USPTO PDF
Audio Engineering Breakdown~1 min listen

Listen to the narrated mechanical breakdown and civilizational context

Engineering Analysis & Physical Principles

How It Works: Step-by-Step Mechanical & Physical Breakdown

The grant solves a mechanical packaging problem: keep prepared film dark inside a portable box, yet let the user load the film holder, wind the shutter spring, release an exposure, advance film, and remove the modules without reopening an uncontrolled light path.
The Core Breakthrough Mechanism

The optical path runs through a front aperture and lens. A hollow cylinder around the lens has matching openings on opposite sides; opaque cylinder wall blocks the path at rest, and a spring-driven half-turn moves the openings across the lens. A rear roller-holder holds the film on supply and winding spools and seals the rear of the tubular case.

Interactive Real-Time Physical Simulation

Drag to rotate · Pinch to zoom · Shared controls update the displayed model
INITIALIZING THREE.JS WEBGL SIMULATION...
Hyperfocal Fixed-Focus Optics & Logarithmic Exposure Law.
Host-Model Telemetry/Computed Readout
Hyperfocal Fixed-Focus Optics & Logarithmic Exposure Law
Hyperfocal Point
Modern Model
12.09 mH[1]
Near Focus Limit
Modern Model
2.40 mD_near[1]
Exposure Value (EV)
Modern Model
EV 10.66EV[1]
Focus Status
Modern Model
SHARP (IN FOCUS)status[1]
Fixed Doublet
Modern Model
57 mmf[1]
Circular Frame
Modern Model
2.5 informat[1]
Shutter Flash
Modern Model
80 mst_shut[1]
Barrel ω
Modern Model
125.664rad/s[1]
Emulsion Photochemical Exposure Energy
∂H / ∂t_exp (host sensitivity)
1 mJ / s
Barrel Shutter Speed0.05 s
Lens Aperture (f-number)9 f/#
Subject Distance3 m
Energy · optics_waves
Shutter Winding Spring Potential
1 W
Rotary Barrel Aperture Exposure
1 W
Barrel Escapement Friction
0 W
Interval ghosts
H12.1 m · [1, 20]
Fidelity / MMS residual
Hyperfocal vs 1888 Kodak No. 1
model12.09 m
reference12 m
residual0.09 m
Coupled channels
spring potential → barrel rotation1 W
Dated scenarios

Detailed Component Architecture

1Front block and chamber
A sectional front block receives the removable lens-and-shutter unit while excluding stray light.

The patent calls the chamber b'. Its matched openings and close-fitting sections create a controlled optical path rather than an open camera interior.

19th-C. Term: Block or diaphragmModern: Light-tight front bulkhead
2Cylindrical shutter
A hollow cylinder with coincident openings surrounds the lens.

At rest the opaque cylinder covers both lens faces. During a controlled half-revolution the aligned openings cross the optical axis, admitting light through the lens before the latch stops the shutter again.

19th-C. Term: Cylindrical shutterModern: Rotary barrel shutter
3Spring drive and release
An external cord winds a spring through a ratchet; a push-pin and latch release and arrest motion.

The ratchet prevents reverse winding. Cam abutments, the pivoted latch, and spring 27 determine the shutter's stop positions and prevent more than a half-revolution per release.

19th-C. Term: Motor mechanismModern: Spring-powered shutter drive
4Roller-holder
The rear assembly carries prepared film, guides it over a platen, and winds it forward.

Supply and winding spools, guide rollers, a platen, a tension device, detaining mechanism, and measuring indicator are mounted between side pieces so the holder can slide into the tubular case.

19th-C. Term: Roller-holderModern: Removable roll-film carrier
Engineering Principles & Equations

Governing Equations & Engineering Principles

Authored explanation paired with its stated mathematical relation

Photographic Lens Relative Aperture & F-Number

Optics & PhotographyClaim 1
Mathematical Governing Law
Terms:
Plain English DecoderHover or tap any highlighted phrase
The equals the divided by the , determining both scene illumination on the roll film and the depth of field.
NN
Lens F-Number
Dimensionless ratio expressing the relative light-gathering power of the camera lens.
dimensionless (f/N)

The original 1888 Kodak camera featured a fixed f/9 doublet lens that provided sharp focus from 8 feet to infinity without requiring manual focusing.

Physical Principle & Engineering Insight

Eastman combined a simple fixed-focus lens with a rotating barrel shutter and 100-exposure roll film holder, democratizing photography with the slogan 'You press the button, we do the rest.'

Historical Context: US 388,850 transformed photography from a specialized chemical craft into a universal consumer medium by introducing portable roll-film cameras and centralized photofinishing.

Rotating Barrel Shutter Exposure Duration & Continuous Roll-Film Capacity

Optics, Photography & Precision MechanismsClaim 1
Mathematical Governing Law
Terms:
Plain English DecoderHover or tap any highlighted phrase
Instantaneous photographic scales with over and , while equals divided by plus margin spacing.
texposuret_{\text{exposure}}
Instantaneous Exposure Duration
Time duration during which the rotating barrel aperture admits light through the lens (1/25 to 1/50 second≈20 to 40 ms1/25\text{ to }1/50\text{ second} \approx 20\text{ to }40\text{ ms})
Seconds (s) / Milliseconds

Fast enough to freeze walking pedestrians and outdoor action without blurring from handheld camera shake.

Physical Principle & Engineering Insight

Before George Eastman's 1888 patent, photography was an arduous craft: photographers carried tripods, darkroom tents, toxic chemicals, and fragile glass plates that had to be coated and developed wet on the spot. Eastman built a lightweight handheld wooden box camera pre-loaded with a 100-exposure flexible roll-film spool, a fixed-focus hyperfocal doublet lens, and a cylindrical rotating barrel shutter. His famous slogan summarized the revolution: 'You press the button, we do the rest.'

Historical Context: US 388850 democratized photography worldwide, invented amateur consumer snapshots, established the Eastman Kodak Company, and supplied the flexible roll film that allowed Thomas Edison to invent motion picture cinema.

Light exclusionAuthored Principle 1
Stated relationΦstray≈0  ⟹  Efilm=πL4N2\Phi_{\text{stray}} \approx 0 \implies E_{\text{film}} = \frac{\pi L}{4 N^2}
Photography requires the sensitive film to see light only through the intended lens aperture. The patent repeatedly protects that condition with overlapping covers, chambers, flush controls, and shutters on both sides of the lens.
Rotational energy storageAuthored Principle 2
Stated relationU=12kθ2andτ=kθU = \frac{1}{2} k \theta^2 \quad \text{and} \quad \tau = k \theta
A wound spring stores mechanical energy. Ratchets transmit winding torque in one direction and the latch-and-abutment system converts the stored energy into a bounded shutter rotation.

Interactive Schematic Sheet (Fig. 1)

Exterior perspective of the rectangular camera case with front block and lens.

1.00x
US 388,850 · FIG. 1100-Exposure SpoolRotary Barrel Shutter
Tap any numbered pin2 Curated Callouts
Callout Pin Inspector

Select Any Numbered Pin

Click pins on the schematic or select from the list below to inspect historical specifications.

Why It Still Matters

The document is a detailed example of system-level camera engineering: optical admission, light sealing, release control, modular service, film transport, and frame indication are treated as coupled mechanisms rather than as an isolated lens or shutter.

Legal Claims Decoder (41 Numbered Claims)

Compare dense legalistic claims directly with decoded plain-English functional specifications.
Claim #1Independent Master Claim
1/41
Verbatim Historical Legal Text
“The combination, to form a camera such as described, of a tubular case or box closed at one end by a detachable film-holder and at the other by a block or end piece, and a removable shutter and lens-support held within a chamber in said block or end piece.”
Plain English Engineering Translation
Claim 1 protects the complete modular camera: a tubular case is closed at the rear by the detachable film-holder, at the front by a block or end piece, and the removable lens-support and shutter sit in that front chamber. The legal combination is the three-part light-tight body, not merely any one component.
Key Protected Innovations:
Tubular case with two removable end modulesFront-chamber lens-support and shutter

The Historical Bottleneck

The source identifies the need for a simple, compact, readily portable camera that can hold prepared film while excluding unwanted light from the exposing chamber.

Why Prior Art Failed

  • •The pinned facsimile focuses directly on the mechanical improvements and does not document an explicit comparative prior-art history in its opening preamble.
  • •The document omits a detailed survey of competing patent claims from contemporaneous manufacturers, such as those by Scovill or Anthony, which might have defined the technical baseline of the era.
The Breakthrough Insight
“Eastman combines a removable front lens-and-shutter module with a removable rear roller-holder in a tubular, light-tight case.”
After the Grant
The pinned facsimile documents the camera apparatus itself; historical litigation regarding nitrocellulose film chemistry is separate from this apparatus grant and has no primary repository packet.
Civilizational Impact
The grant documents a complete mechanical architecture for a portable prepared-film camera, including exposure, light sealing, and film handling.
Further Context
  • The printed specification cites Eastman's Patents Nos. 317,019, 317,050, and 316,933 and a prior application, Serial No. 199,329, filed April 19, 1886.