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.

An instrument that measures time in a precise manner.

Chronometer

An instrument that measures time in a precise manner.

An empty classroom.

Classroom

An empty classroom.

This clock is engraved and used as a centerpiece to a candelabrum. The figures are made of bronze and the dial is gold.

Clock

This clock is engraved and used as a centerpiece to a candelabrum. The figures are made of bronze and…

This clock is used on a table.

Clock

This clock is used on a table.

This clock is made out of bronze with a design of a group of figures supporting a starry globe, with serpent clock hands.

Clock

This clock is made out of bronze with a design of a group of figures supporting a starry globe, with…

An illustration of a Roman Numeral clock showing 11:15.

Clock 11:15

An illustration of a Roman Numeral clock showing 11:15.

An illustration of a Roman Numeral clock showing 11:50.

Clock 11:50

An illustration of a Roman Numeral clock showing 11:50.

An illustration of a Roman Numeral clock showing 2:30.

Clock 2:30

An illustration of a Roman Numeral clock showing 2:30.

An illustration of a Roman Numeral clock showing 2:50.

Clock 2:50

An illustration of a Roman Numeral clock showing 2:50.

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

Clock 5:10

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

An illustration of a Roman Numeral clock showing 6:40.

Clock 6:40

An illustration of a Roman Numeral clock showing 6:40.

An illustration of a Roman Numeral clock showing 7:30.

Clock 7:30

An illustration of a Roman Numeral clock showing 7:30.

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.

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…

A cockoo bird perched on a branch.

Cuckoo

A cockoo bird perched on a branch.

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…

This dial features a clock face which is the part of an analog clock that displays the time through the use of a fixed numbered dial and moving hands. In its most basic form, the dial is numbered 1-12.

Watch and Clock Dial

This dial features a clock face which is the part of an analog clock that displays the time through…

This is a timepiece that shows the time of the day, using a small electric motor

Secondary Electric Clock

This is a timepiece that shows the time of the day, using a small electric motor

An electric clock is a clock that is powered by electricity instead of powered manually or by other sources of energy, specifically in order to wind the mainspring or to drive the pendulum or oscillator.

Electric Energy Clock

An electric clock is a clock that is powered by electricity instead of powered manually or by other…

"A front view of a common English house clock with the face taken off, showing the repeating or rack striking movement. Here, M is the hourwheel on the pipeof which the minute-hand is set, N the reversed hour-wheel, and n its pinion, driving the 12-hour wheel H, on whose socket is ficed what is called the snail Y, which belongs to the striking work exclusively. The hammer is raised by the eight pins in the rim of the second wheel in the striking train, in the manner which is obvious." — Encyclopedia Britanica, 1893

English House Clock

"A front view of a common English house clock with the face taken off, showing the repeating or rack…

"Waltham Lever Escapement. A device for the governing of speed is the one thing on which accurate time measuring depends." -Hill, 1921

Lever Escapement

"Waltham Lever Escapement. A device for the governing of speed is the one thing on which accurate time…

"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…

"E represents the scape-wheel turning in a minute, and e its pinion, which is driven by the wheel D having a pinion d driven by the wheel C, which we may suppose to turn in an hour. The arbors of the scape-wheel and hour-wheel are distinct, their pivots-meeting in a bush fixed somewhere between the wheels. The pivots of the wheel, D are set in the frame AP, which rides on the arbors of the hour-wheel and scape-wheel, or on another short arbor between them. The hour-wheel also drives another wheel G, which again drives the pinion f on the arbor which carries the two arms f A, f B; and on the same arbor is set a fly with a ratchet, like a common striking fly, and the numbers of the teeth are so arranged that the fly will turn once for each turn of the scapewheel. The ends of the remontoire arms f A, f B are capable of alternately passing the notches cut half through the arbor of the scape-wheel, as those notches successively come into the proper position at the end of every half minute; as soon as that happens the-hour-wheel raises the movable wheel D and its frame through a small angle; but nevertheless, that wheel keeps pressing on the scape-wheel as if it were not moving, the point of contact of the wheel C and the pinion d being the fulcrum or center of motion of the level A d P." — Encyclopedia Britanica, 1893

Gravity Train Remontoire

"E represents the scape-wheel turning in a minute, and e its pinion, which is driven by the wheel D…

Gulliver's watch is being taken away. From <em>Gulliver's Travels</em> by Dean Swift.

Gulliver's Watch

Gulliver's watch is being taken away. From Gulliver's Travels by Dean Swift.

"The click barrel-ratchet R is set upon another larger ratchet-wheel, with its teeth pointing the opposite way, and its click rT is set in the clock-frame. That ratchet is connected with the great wheel by a spring ss' pressing against the two pins s in the ratchet and s' in the wheel. When you wind up the weight, the click Tr prevents the ratchet from turning back or to the right; and as the spring ss' is kept by the weight in a state of tension equivalent to the weight itself it will drive the wheel to the left for a short distance, when its end s is held fast, with the same force as if that end was pulled forward by the weight; and as the great wheel has to move very little during the short time the clock is winding, the spring will keep the clock going long enough." &mdash; Encyclopedia Britanica, 1893

Harrison's Going-Ratchet

"The click barrel-ratchet R is set upon another larger ratchet-wheel, with its teeth pointing the opposite…

Clock from, "Hickory Dickory Dock."

Hickory Dickory Dock

Clock from, "Hickory Dickory Dock."

This clock and inkstand is was designed for a library table.

Clock and Inkstand

This clock and inkstand is was designed for a library table.

A shop in Lucerne, Switzerland selling Longines watches.

Watch Store in Lucerne, Switzerland

A shop in Lucerne, Switzerland selling Longines watches.

Watch belonging to Martha Custis Washington (June 2, 1731 &ndash; 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…

Old clock with Roman numerals, 11:58.

Old clock

Old clock with Roman numerals, 11:58.

"A pendulum has a strong tendency to maintain its plane of oscillation, a fact that has been used in the experimental demonstration of the earth upon its axis. The chief function of the wheel-work of a clock is to register the number of vibrations of the pendulum. If the clock gains time, the pendulum is lengthened by lowering the bob, if it loses time, the pendulum is shortened by raising the bob." &mdash; Avery, 1895

Pendulum

"A pendulum has a strong tendency to maintain its plane of oscillation, a fact that has been used in…

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…

"The front view of a large quarter clock of Sir E. Beckett's design, with all the wheels on the great horizontal bed, a gravity escapemen, and a compensated pendulum.  They are made in two sizes, one wih a great striking wheels 18 inches wide, and the other 14. The striking is done by cams cast on the great wheels, about 1.125 inch broad in the large-sized clocks, which are strong enough for an hour bell of thirty cwt., and corresponding quarters. Wire ropes are used, not only because they last longer, if kept greased, but because a sufficient number of coils will go on a barrel of less than half the length that would be required for hemp ropes of the same strength, without overlapping, which it is as well to avoid, if possible, though it is not so injurious to wire ropes as it is to hemp ones. by this means also the striking cams can be put on the great wheel, instead of the second wheel, which saves more in friction than could be imagined by any one who had not tried both. In clocks of the common construction two-thirds of the power is often wasted in friction and in the bad arrangement of the hammer work, and the clock is wearing itself out in doing nothing." &mdash; Encyclopedia Britanica, 1893

Quarter Clock

"The front view of a large quarter clock of Sir E. Beckett's design, with all the wheels on the great…

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…

"Michel-Angelo assumed such considerable and prominent position by his genius and authority, that his example necessarily entailed imitation and produced effects on subsequent times. When his deviations were moderate, they were considered by his imitators merely as marks of the originality of his wonderful talent, and by this means proved stepping-stones to the degeneration which marked the ensuing period of the Roccoco style. Amongst his architectural works, the design of the Capitol at Rome, with its wings, may be considered as the most pleasing, whilst as a testimony to his lofty genius the mighty and glorious dome of St. Peter's at Rome, which has no rival in the world, must be adducted as a striking instance."

Modern Capital at Rome

"Michel-Angelo assumed such considerable and prominent position by his genius and authority, that his…

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 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 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 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 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 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 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…

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…

"A form of Sun-dial that is as god to-day as any dial for determining noon." -Bodmer, 1917

Modern Sundial

"A form of Sun-dial that is as god to-day as any dial for determining noon." -Bodmer, 1917