Round clock with Roman numerals showing time 12:56

Clock 12:56

Round clock with Roman numerals showing time 12:56

Round clock with Roman numerals showing time 12:57

Clock 12:57

Round clock with Roman numerals showing time 12:57

Round clock with Roman numerals showing time 12:58

Clock 12:58

Round clock with Roman numerals showing time 12:58

Round clock with Roman numerals showing time 12:59

Clock 12:59

Round clock with Roman numerals showing time 12:59

"Were the Earth's orbit a perfect circle, and her axis perpendicular to the plane of this orbit, the days would be of a uniform length, and there would be no difference between the clock and the Sun." -Comstock 1850

Suns in the Equator and Ecliptic

"Were the Earth's orbit a perfect circle, and her axis perpendicular to the plane of this orbit, the…

"The Morse register is represented [here]. The armature, A , is supported at the end of a lever, and over the cores of the magnet bobbins, M. A spring, S, lifts the armature when the cores are demagnetized on the breaking of the circuit by the operator at the key. When A is pulled down by M, a style or pencil at P is pressed against R, a paper ribbon that is drawn along by clock work. this style may be made to record upon the paper a dot-and-dash communication sent by the operator at a key, perhaps hundreds of miles away." -Avery 1895

Morse Telegraph Register

"The Morse register is represented [here]. The armature, A , is supported at the end of a lever, and…

"A key is used to turn the cone, B. By doing so it wraps the chain around the cone and tightly coils the spring inside the barrel, A. The spring draws the chain off of the cone turning the barrel." —Quackenbos 1859

The Fusee

"A key is used to turn the cone, B. By doing so it wraps the chain around the cone and tightly coils…

"The town clock of Athens in the Hellenistic Age." -Breasted, 1914

Athenian Town Clock

"The town clock of Athens in the Hellenistic Age." -Breasted, 1914

The clock of Quaker, William Penn.

Penn's Clock

The clock of Quaker, William Penn.

The clock struck one and the mouse ran down.

Hickory Dickory Dock

The clock struck one and the mouse ran down.

Illustration of a child washing face at 7:00. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 7:00 Story Problem

Illustration of a child washing face at 7:00. It can be used to write mathematics story problems involving…

Illustration of a child eating breakfast at 8:00. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 8:00 Story Problem

Illustration of a child eating breakfast at 8:00. It can be used to write mathematics story problems…

Illustration of a child going up stairs at 9:00. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 9:00 Story Problem

Illustration of a child going up stairs at 9:00. It can be used to write mathematics story problems…

Illustration of a child reading at school at 10:00. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 10:00 Story Problem

Illustration of a child reading at school at 10:00. It can be used to write mathematics story problems…

Illustration of a child reading at school at 11:00. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 11:00 Story Problem

Illustration of a child reading at school at 11:00. It can be used to write mathematics story problems…

Illustration of a child running at 12:00 noon. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 12:00 Noon Story Problem

Illustration of a child running at 12:00 noon. It can be used to write mathematics story problems involving…

Illustration of a child walking at 1:00. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 1:00 Story Problem

Illustration of a child walking at 1:00. It can be used to write mathematics story problems involving…

Illustration of a child writing roman numerals at 2:00. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 2:00 Story Problem

Illustration of a child writing roman numerals at 2:00. It can be used to write mathematics story problems…

Illustration of a child making a clock face at 3:00. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 3:00 Story Problem

Illustration of a child making a clock face at 3:00. It can be used to write mathematics story problems…

Illustration of a child hugging his mother at 4:00. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 4:00 Story Problem

Illustration of a child hugging his mother at 4:00. It can be used to write mathematics story problems…

Illustration of a child hauling wood at 5:00. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 5:00 Story Problem

Illustration of a child hauling wood at 5:00. It can be used to write mathematics story problems involving…

Illustration of a child running with a pail at 6:00. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 6:00 Story Problem

Illustration of a child running with a pail at 6:00. It can be used to write mathematics story problems…

Illustration of a child playing toy soldiers at 7:00. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 7:00 Story Problem

Illustration of a child playing toy soldiers at 7:00. It can be used to write mathematics story problems…

Illustration of a child yawning at 8:00. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 8:00 Story Problem

Illustration of a child yawning at 8:00. It can be used to write mathematics story problems involving…

Illustration of a child sleeping all night: 9:00pm to 7:00am. It can be used to write mathematics story problems involving telling time and roman numerals.

Telling Time 9:00pm to 7:00am Story Problem

Illustration of a child sleeping all night: 9:00pm to 7:00am. It can be used to write mathematics story…

The image represents the horizontal clock face system. The bottom is the firing line and the numbers of the clock references the position of other objects.

Horizontal Clock Face System

The image represents the horizontal clock face system. The bottom is the firing line and the numbers…

A round clock face with dash marks showing no time.

Blank Clock

A round clock face with dash marks showing no time.

A round clock face with numbers showing no time.

Blank Clock

A round clock face with numbers showing no time.

A round clock face with roman numerals showing no time.

Blank Clock

A round clock face with roman numerals showing no time.

"Comparative time, when noon in Chicago." -Foster, 1921

Comparative Time

"Comparative time, when noon in Chicago." -Foster, 1921

"Comparative time, when noon in Toronto." -Foster, 1921

Comparative Time

"Comparative time, when noon in Toronto." -Foster, 1921

A clock that reads 10:38.

10:38

A clock that reads 10:38.

The Barocco clock-case of the 17th century had a case for protecting the interior work against dust and for giving the clock a more pleasing aspect. This clock was placed on a pedestal.

Barocco Clock-Case

The Barocco clock-case of the 17th century had a case for protecting the interior work against dust…

This Modern clock-case was mostly made with a roof.

Modern Clock-Case

This Modern clock-case was mostly made with a roof.

This Modern clock-case was made with metal ornaments. It was Dome-shaped and crowned by a small bell-turret.

Modern Clock-Case

This Modern clock-case was made with metal ornaments. It was Dome-shaped and crowned by a small bell-turret.

This Modern clock-case had a hanging-case intended for both weight and pendulum clocks.

Modern Clock-Case

This Modern clock-case had a hanging-case intended for both weight and pendulum clocks.

This Toilet-stand clock-case was made during the German Renaissance in 1597. A slender tall cabinet, the upper and lower parts of which are provided with doors, which holds various necessary objects, while the center takes the form of a niche. Inside the niche hangs a metal water-reservoir with a lid and a drain. It also includes metal wrought-iron towel-holders.

Toilet-Stand Clock-Case

This Toilet-stand clock-case was made during the German Renaissance in 1597. A slender tall cabinet,…

This Toilet-stand clock-case was made during the German Renaissance. Made of various colored wood, it was a slender tall cabinet where the upper and lower parts included doors, which holds various necessary objects. The center takes the form of a niche and inside the niche hangs a metal water-reservoir with a lid and a drain. It also includes metal wrought-iron towel-holders.

Toilet-Stand Clock-Case

This Toilet-stand clock-case was made during the German Renaissance. Made of various colored wood, it…

An illustration of a pocket watch.

Pocket Watch

An illustration of a pocket watch.

In addition to being a parish church in the Diocese of Ely, it is the University Church for the University of Cambridge. As such it has a minor role in the University's legislation: for example, University Officers must live within 20 miles of Great St. Mary's, and undergraduates within three. The church also hosts University Sermons, and houses the University Organ and the University Clock. The latter chimes the Cambridge Chimes which were later used by the clock tower of the Houses of Parliament ("Big Ben").

St. Mary's Church, Cambridge

In addition to being a parish church in the Diocese of Ely, it is the University Church for the University…

Watch belonging to Martha Custis Washington (June 2, 1731 – May 22, 1802), the wife of George Washington, the first president of the United States. Although the title was not coined until after her death, Martha Washington is considered to be the first First Lady of the United States. During her lifetime, she was simply known as "Lady Washington."

Martha Washington's Bridal Watch

Watch belonging to Martha Custis Washington (June 2, 1731 – May 22, 1802), the wife of George…

The Tower of the Winds, also called horologion (timepiece), is an octagonal Pentelic marble clocktower on the Roman agora in Athens. The structure features a combination of sundials, a water clock and a wind vane. It was supposedly built by Andronicus of Cyrrhus around 50 BC, but according to other sources might have been constructed in the 2nd century BC before the rest of the forum.

Tower of the Winds

The Tower of the Winds, also called horologion (timepiece), is an octagonal Pentelic marble clocktower…

A sundial is a device that measures time by the position of the Sun. In common designs such as the horizontal sundial, the sun casts a shadow from its style (a thin rod or a sharp, straight edge) onto a flat surface marked with lines indicating the hours of the day. As the sun moves across the sky, the shadow-edge progressively aligns with different hour-lines on the plate. Such designs rely on the style being aligned with the axis of the Earth's rotation. Hence, if such a sundial is to tell the correct time, the style must point towards true North (not the north or south magnetic pole) and the style's angle with horizontal must equal the sundial's geographical latitude.

Sundial

A sundial is a device that measures time by the position of the Sun. In common designs such as the horizontal…

In the common vertical dial, the shadow-receiving plane is aligned vertically; as usual, the gnomon's style is aligned with the Earth's axis of rotation. As in the horizontal dial, the line of shadow does not move uniformly on the face; the sundial is not equiangular.

Vertical South Dial

In the common vertical dial, the shadow-receiving plane is aligned vertically; as usual, the gnomon's…

In polar dials, the shadow-receiving plane is aligned parallel to the gnomon-style. Thus, the shadow slides sideways over the surface, moving perpendicularly to itself as the sun rotates about the style. As with the gnomon, the hour-lines are all aligned with the Earth's rotational axis. When the sun's rays are nearly parallel to the plane, the shadow moves very quickly and the hour lines are spaced far apart. The direct East- and West-facing dials are examples of a polar dial. However, the face of a polar dial need not be vertical; it need only be parallel to the gnomon.

Polar Dials

In polar dials, the shadow-receiving plane is aligned parallel to the gnomon-style. Thus, the shadow…

An illustration of a section of the interior of a large house clock.

House Clock

An illustration of a section of the interior of a large house clock.

In horology, the recoil or anchor escapement is a type of escapement used in pendulum clocks. An escapement is the mechanism in a mechanical clock that maintains the swing of the pendulum and advances the clock's wheels at each swing.

Anchor Escapement

In horology, the recoil or anchor escapement is a type of escapement used in pendulum clocks. An escapement…

An illustration of the interior of a common English House Clock.

English House Clock

An illustration of the interior of a common English House Clock.

An electrical remontoire can be either a gravity or spring type. In it, the weight or spring is rewound electrically, with a motor or solenoid. It is used in clocks with traditional mechanical movements which are run on electricity.

Electrical Remontoire

An electrical remontoire can be either a gravity or spring type. In it, the weight or spring is rewound…

An illustration of Hope Jone's dial-driving device. "Each time that a current is sent by the master clock, the electromagnet B attracts the pivoted armature C, and then the current ceases the lever D with the projecting arm E is driven back to its old position by the spring F, thus driving the wheel A forward one division. G is a back stop click, and H, I fixed stops." —Britannica, 1910

Dial Driving Device

An illustration of Hope Jone's dial-driving device. "Each time that a current is sent by the master…

"In 1872 Penaud discarded the rigid screws in favour of elastic ones...Penaud also india-rbber under torsion for the whale-bone and clock springs of the smaller model is remarkable for its lightness, simplicity and power." -Britannica, 1910

Screw-Model

"In 1872 Penaud discarded the rigid screws in favour of elastic ones...Penaud also india-rbber under…

This trophy clock panel was designed during the French Renaissance. Trophies were tokens of victory that were used to decorate monuments connected with war.

Trophy Clock Panel

This trophy clock panel was designed during the French Renaissance. Trophies were tokens of victory…

This music trophy clock panel was designed during the French Renaissance. Trophies were tokens of victory that were used to decorate monuments connected with war.

Music Trophy Clock Panel

This music trophy clock panel was designed during the French Renaissance. Trophies were tokens of victory…

This strap-work clock-case tablet is a hammered metal that was designed during the French Renaissance period.

Clock-Case Strap-Work Tablet

This strap-work clock-case tablet is a hammered metal that was designed during the French Renaissance…

This strap-work clock-case tablet is a stamped metal that is modern.

Clock-Case Strap-Work Tablet

This strap-work clock-case tablet is a stamped metal that is modern.

A piece in clocks and watches that converts rotational motion into oscillation, as in a pendulum.

Recoiling Escapement

A piece in clocks and watches that converts rotational motion into oscillation, as in a pendulum.

A piece in clocks and watches that converts rotational motion into oscillation, as in a pendulum.

Deadbeat Escapement

A piece in clocks and watches that converts rotational motion into oscillation, as in a pendulum.

"Files. a, cotter-file when large, and verge- or pivot-file when small; b, square file (parallel or taper); c, banking or watch-pinion file when parallel, and knife-file when tape; d, half-round, nicking, piercing, or round-off file; e, round, gulleting, or rat-tail file; f, triangular, three-square, or saw file; g, equaling, clock-pinion, or endless-screw file when parallel, and slitting, entering, warding, or barrel-hole file when tape; h, cross- or double-half-round file; i, screw-head, feather-edge, or slitting file." -Whitney, 1911

Types of Files

"Files. a, cotter-file when large, and verge- or pivot-file when small; b, square file (parallel or…

An illustration of a Roman Numeral clock showing five o'clock (5:00).

Clock 5:00

An illustration of a Roman Numeral clock showing five o'clock (5:00).

An illustration of a Roman Numeral clock showing 5:10.

Clock 5:10

An illustration of a Roman Numeral clock showing 5:10.