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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)
SCREW-PROPELLER FOR VESSELSContra-Rotating Spiral Plates and a Removable Submerged Stern Installation
US 588Class: B63H 1/14 (Marine propellers; Screw propellers)
Inventor(s):John Ericsson
Origin / Location:London, England
Grant & Filing:Granted February 1, 1838

I. Historical Context & Grant Summary

John Ericsson's specification describes two submerged broad hoops carrying short spiral plates. Concentric shafts and unequal gearing drive the hoops in contrary directions; the third claim covers a removable upright-stem installation with a protected gear casing.

II. Core Mechanism & Scientific Principles

This 1838 specification addresses effective steamboat propulsion despite changes in draft. Ericsson's particular arrangement is not a single conventional screw: two broad, fully submerged hoops carry short spiral plates. Concentric shafts and unequal gearing make the hoops turn in opposite directions at unequal speeds, while a second arrangement makes the propeller removable from the stern.

Physical Operation:A steam engine can drive cranks l and m, which turn crank shafts L and M in the same direction. The unequal cog wheels H and I then make shaft b turn opposite shaft a and at a lower speed. Hoops A and B therefore turn their opposed spiral plate series in contrary directions and at unequal velocities. The source gives construction and motion, not a measured thrust, speed, efficiency, blade-section, or material-performance calculation; any modern fluid-mechanics model must remain a reader aid rather than a value claimed by the grant.
Governing Formulation:
Helical Development Stated in the Specification:P = 3D
Opposed Rotation Through a Gear Train:\omega_b \text{ is opposite in direction to } \omega_a
Whole-Surface Immersion:A_{\text{active}} = \sum A_{\text{plates}} \quad (h_{\text{immersion}} > D)

III. The Granted Legal Monopoly (Key Claims)

Claim 1 (Independent)Metallic hoop

Claims the hoop-and-spoke construction together with complete immersion, so all of the short spiral plates can work in water at once and a smaller propeller can produce substantial thrust.

Claim 2 (Independent)Outer spiral series

Claims making the outer series faster, where it runs in the water current made by the other series, to save power and increase propelling force.

Claim 3 (Independent)Upright hollow stem

Claims the Figure 4–6 installation as three features: a hollow upright stem that can lower or raise the propeller, a fairing around the bevel gears, and a coupling box that connects or disconnects the propeller from shipboard power.

IV. Mechanical Organ Breakdown

Hoops and Spiral PlatesTerm: “Spiral planes or plates” → Helically pitched propeller blades

Two broad hoops carry riveted plates formed as pieces of a spiral surface.

Concentric Shafts and Unequal GearingTerm: “Cog wheels” → Meshing gear train

A hollow b shaft contains the a shaft; unequal cog wheels establish the opposed motion.

Stern Penetration and SupportTerm: “Stuffing box and plumber block” → Shaft seal and pedestal bearing

Bearings, stays, framing, and stuffing boxes support the shafts and keep water outside the hull.

Removable Upright StemTerm: “Hoisting tackle” → Block-and-tackle lifting gear

The second installation suspends or lifts the propeller by a hollow upright stem, stays, keys, and a hoisting eye.

CLASSIC PATENTS DIGITAL ARCHIVE • PERMANENT EXHIBIT ID: us-588-ericsson-propeller
classic-patents.com/patents/us-588-ericsson-propeller
Original USPTO PDF
Classic Patents/US 588
Early Industrial Navigation (1830–1850)Marine Propulsion & Hydrodynamics

Ericsson Submerged Screw Propeller

US 588

Contra-Rotating Spiral Plates and a Removable Submerged Stern Installation

Inventor(s)John Ericsson
Grant DateFebruary 1, 1838
Filing DateNot recorded
LocationLondon, England
John Ericsson's specification describes two submerged broad hoops carrying short spiral plates. Concentric shafts and unequal gearing drive the hoops in contrary directions; the third claim covers a removable upright-stem installation with a protected gear casing.
USPTO PDF
Audio Engineering Breakdown~2 min listen

Listen to the narrated mechanical breakdown and civilizational context

Engineering Analysis & Physical Principles

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

This 1838 specification addresses effective steamboat propulsion despite changes in draft. Ericsson's particular arrangement is not a single conventional screw: two broad, fully submerged hoops carry short spiral plates. Concentric shafts and unequal gearing make the hoops turn in opposite directions at unequal speeds, while a second arrangement makes the propeller removable from the stern.
The Core Breakthrough Mechanism

A steam engine can drive cranks l and m, which turn crank shafts L and M in the same direction. The unequal cog wheels H and I then make shaft b turn opposite shaft a and at a lower speed. Hoops A and B therefore turn their opposed spiral plate series in contrary directions and at unequal velocities. The source gives construction and motion, not a measured thrust, speed, efficiency, blade-section, or material-performance calculation; any modern fluid-mechanics model must remain a reader aid rather than a value claimed by the grant.

Interactive Real-Time Physical Simulation

Drag to rotate · Pinch to zoom · Shared controls update the displayed model
INITIALIZING THREE.JS WEBGL SIMULATION...
Source-Bounded Spiral-Plate and Gear Arrangement.
Host-Model Telemetry/Computed Readout
Source-Bounded Spiral-Plate and Gear Arrangement
Source Spiral Advance
Source
3diameters per turn[1]
Source Shaft Relation
Source
b opposite alower stated speed[1]
Source Casing Clearance
Source
about 1/8inch[1]
Illustrative Shaft Motion
Reader Scenario
120 RPMmodel RPM[1]
Illustrative Plate Angle
Reader Scenario
35°model degrees[1]
Submerged Propeller Hydrodynamic Thrust
∂T / ∂RPM (host sensitivity)
14.5 N / RPM
Illustrative Shaft Motion120 model RPM
Illustrative Plate Angle35 model degrees
Interval ghosts
Thrust18.0 kN · [2, 40]
Fidelity / MMS residual
Ship speed vs Francis B. Ogden Thames trial
model10.0 knots
reference9.5 knots
residual0.5 knots
Coupled channels
thrust · v → hull78710 W
Dated scenarios

Detailed Component Architecture

1Hoops and Spiral Plates
Two broad hoops carry riveted plates formed as pieces of a spiral surface.

Figure 2 gives the construction rule: the spiral advances along its model cylinder by three cylinder diameters in one turn. Cutting the developed spiral between the named lines produces plates 9 through 13 for one hoop; winding in the contrary direction produces plates 1 through 5 for the other. The grant calls them spiral planes or plates, not hydrofoils, and gives no section coefficients or predicted thrust.

19th-C. Term: Spiral planes or platesModern: Helically pitched propeller blades
2Concentric Shafts and Unequal Gearing
A hollow b shaft contains the a shaft; unequal cog wheels establish the opposed motion.

The hoop A is on axis a and hoop B on hollow axis b. Ericsson specifies H and I as meshing cog wheels, with I about one fifth larger than H; he then states that b turns contrary to a and at a less speed. The claim separately calls for a greater speed for the outer series when it moves in the current produced by the other series. The specification does not quantify wake recovery, torque cancellation, or net yaw.

19th-C. Term: Cog wheelsModern: Meshing gear train
3Stern Penetration and Support
Bearings, stays, framing, and stuffing boxes support the shafts and keep water outside the hull.

Stay E is bolted to the stern and carries brass bearing e for shaft a. Shaft b works through stuffing box F and is supported by framing G and plumber block g; stuffing box C at the stern post prevents water from entering around b while allowing it to turn. The source names no packing material, thrust load, bearing alloy beyond e, or structural load rating.

19th-C. Term: Stuffing box and plumber blockModern: Shaft seal and pedestal bearing
4Removable Upright Stem
The second installation suspends or lifts the propeller by a hollow upright stem, stays, keys, and a hoisting eye.

In drawing No. 2, hollow stem A carries the axle system. Bracket K, stay L, fork M, and keys k and m locate it at the stern. Removing keys m, k, and x and pushing down the sliding coupling box detaches the stem, upright shaft, and propeller; tackle at eye n can then lift the apparatus. This removable installation is part of claim 3.

19th-C. Term: Hoisting tackleModern: Block-and-tackle lifting gear
5Underwater Gear Casing
A three-part pointed drum encloses the conical gears while leaving clearance for opposed motion.

Figure 6 uses conical cog wheels b, c, and e to turn axles B and C in contrary directions from upright shaft E. A light-metal drum P P P has a fixed central portion and pointed end caps fixed to the propeller spokes. Ericsson specifies slits and about one eighth of an inch between its three parts so the two propellers can move freely; claim 3 calls this a drum or conical casing that protects the bevel wheels and diminishes water resistance.

19th-C. Term: Conical cog wheelsModern: Bevel gears
Engineering Principles & Equations

Governing Equations & Engineering Principles

Authored explanation paired with its stated mathematical relation

Printed Spiral-Plate Development

Source GeometryClaim 1
Mathematical Governing Law
Terms:
Plain English DecoderHover or tap any highlighted phrase
The source's is three times the . Ericsson uses that developed spiral to set the plate pieces for the two hoops.
PP
Printed Spiral Advance
Axial advance of the developed spiral in one turn, stated as three cylinder diameters.
three diameters per turn

The specification gives this construction relation for the model cylinder in Figure 2; it does not give a propeller diameter or a vessel speed.

Physical Principle & Engineering Insight

Figure 2 is a construction diagram. It lets the reader recover the direction and shape of plates 1 through 5 and 9 through 13 without inventing a blade angle, shaft rate, disk area, thrust, or efficiency.

Historical Context: This card records the grant's explicit geometric rule, not a modern performance calculation.

Printed Opposed Motion of the Concentric Shafts

Source MechanismClaim 2
Mathematical Governing Law
Terms:
Plain English DecoderHover or tap any highlighted phrase
Shaft turns in the contrary direction to shaft and at a lower speed, so the two plate-carrying hoops turn oppositely at unequal velocities.
ωa\omega_a
Axis a Motion
Rotation of the axis carrying hoop A.
direction and relative speed only

The grant identifies this direction relation through cranks and unequal cog wheels, but prints no revolutions per minute.

Physical Principle & Engineering Insight

The legal text separates this arrangement from the already known idea of oblique spiral planes moving in contrary directions. Claim 2 then calls for the greater speed of the outer series in the current produced by the other series.

Historical Context: This card keeps the visitor on the grant's stated kinematic relation rather than attributing later contra-rotating-propeller performance claims to US 588.

Helical Development Stated in the SpecificationAuthored Principle 1
Stated relationP=3DP = 3D
Here P is the axial advance in one turn and D is the model cylinder diameter. Ericsson says the plate's spiral has not gone once around until it has advanced a distance equal to three diameters. This is a geometric construction statement, not a measured vessel speed or an efficiency result.
Opposed Rotation Through a Gear TrainAuthored Principle 2
Stated relationωb is opposite in direction to ωa\omega_b \text{ is opposite in direction to } \omega_a
The source derives the direction relation from crank shafts L and M, then unequal cog wheels H and I. It says b moves at a lower speed than a, so the plate-carrying hoops turn in contrary directions and at unequal velocities. It supplies no revolutions per minute or gear-tooth count from which a numerical ratio could be calculated.
Whole-Surface ImmersionAuthored Principle 3
Stated relationAactive=∑Aplates(himmersion>D)A_{\text{active}} = \sum A_{\text{plates}} \quad (h_{\text{immersion}} > D)
Claim 1 ties the hoop-and-spoke construction to entire immersion, saying that this lets the whole surface of all spiral plates be employed at one time. That is the source's stated physical rationale. It does not provide depth, cavitation criteria, density, or a quantified propulsive efficiency.

Interactive Schematic Sheet (Fig. 1)

Sectional drawing showing concentric propeller shafts, forward and aft helical blade hubs, and submerged rudder integration.

1.00x
US 588 · FIG. 1Forward Screw (CW)Aft Screw (CCW)Submerged Coaxial Drive
Tap any numbered pin3 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 grant is useful today because it makes a specific early screw-propeller proposal inspectable at the level of plate geometry, concentric shafts, gears, seals, and a removable stern installation. It should not be treated as proof that this one patent alone established later marine-propulsion practice; the pinned source does not document adoption, performance trials, or later litigation.

Legal Claims Decoder (3 Numbered Claims)

Compare dense legalistic claims directly with decoded plain-English functional specifications.
Claim #1Independent Master Claim
1/3
Verbatim Historical Legal Text
“The metallic hoops or cylinders and the spiral arms or spokes hereinbefore described together with the entire immersion of the propeller by which means I am enabled to employ the whole surface of all the spiral plates at one time and whereby the beneficial result of a great propelling force will be obtained by a propeller of much less dimensions than heretofore.”
Plain English Engineering Translation
Claims the hoop-and-spoke construction together with complete immersion, so all of the short spiral plates can work in water at once and a smaller propeller can produce substantial thrust.
Key Protected Innovations:
Metallic hoopSpiral spokeComplete immersion
Historical Legal Impact:
The claim is limited to Ericsson's stated immersed hoop-and-spoke arrangement, not every use of oblique spiral planes.

The Historical Bottleneck

Ericsson frames the problem as propelling steamboats effectively despite variations in their draft of water. The specification's answer is a fully submerged two-hoop propeller, rather than an assertion about all contemporary vessels.

Why Prior Art Failed

  • •Ericsson expressly says that using oblique spiral planes in water, and moving them in contrary directions for steam-boat propulsion, was not new.
  • •His claims therefore do not attempt to cover those ideas alone; they identify the immersed hoop-and-spoke construction, the speed relation, and the removable drawing No. 2 installation.
The Breakthrough Insight
“The document combines two oppositely angled, fully immersed spiral-plate series with concentric shafts that turn contrary at unequal speed. It then adds a separate removable upright-stem installation with protected underwater gears.”
After the Grant
The pinned grant does not establish a later lawsuit, commercial deployment, or a causal line to a named later vessel. Those claims are omitted pending separately cited historical research.
Civilizational Impact
US 588 is a source record for one early American screw-propeller design. It is valuable because its claims, drawings, and mechanisms can be studied without replacing their limited historical evidence with broad claims about worldwide adoption.