# A Rudimentary Treatise on Clocks, Watches, and Bells Trivia Quiz Questions and Answers

What is the name of the device that regulates the velocity of a clock train by using vanes that are resisted by the air?

• Pendulum
• Escapement
• Fan fly
• Flywheel

Correct Answer Explanation: A fan fly is a device that regulates the velocity of a clock train by using vanes that are resisted by the air. The fan fly is a simple and effective device that is still used in many clocks today.

What is the name of the difference between true and mean solar time for each day?

• Equation of time
• Sidereal time
• Solar time
• Mean time

Correct Answer Explanation: The difference between true and mean solar time for each day is called the Equation of time. The Equation of time is caused by the Earth’s elliptical orbit around the Sun and the tilt of the Earth’s axis.

What is the name of the point in a pendulum that would oscillate in the same time as a simple pendulum of the same length?

• Center of gravity
• Center of oscillation
• Center of percussion
• Center of mass

Correct Answer Explanation: The center of oscillation of a pendulum is the point that would oscillate in the same time as a simple pendulum of the same length. The center of oscillation is not a fixed point, but rather a relative one that is determined by the axis of suspension.

Which type of escapement provides a more accurate timekeeping mechanism than the recoil escapement?

• Crown-wheel escapement
• Anchor escapement
• Recoil escapement

Correct Answer Explanation: The dead escapement was invented by Graham and provides a more accurate timekeeping mechanism than the recoil escapement. The dead escapement is characterized by the fact that the scapewheel stops momentarily after releasing a tooth. This allows the pendulum to swing freely without being affected by the recoil of the scapewheel.

What is the name of the earliest known escapement, used in clocks before the invention of pendulums?

• Anchor escapement
• Crown-wheel escapement
• Recoil escapement

Correct Answer Explanation: The crown-wheel escapement was the earliest known escapement, used in clocks before the invention of pendulums. It is a simple escapement that consists of a crown wheel with teeth that are engaged by a pallet that is attached to the clock’s verge. The verge is a small rod that is mounted on the clock’s spindle.

What is the name of a large circular loop of very thin steel wire designed to isochronize a pendulum in a dead escapement?

• Loseby’s isochronal spring
• Harrison’s gridiron pendulum
• Compensated pendulum
• Mercurial pendulum

Correct Answer Explanation: Loseby’s isochronal spring was a large circular loop of very thin steel wire designed to isochronize a pendulum in a dead escapement. However, it was ultimately deemed unsuccessful.

What is the name of the variation in a clock’s rate caused by changes in air pressure?

• Circular error
• Barometric error
• Temperature error
• Gravity error

Correct Answer Explanation: The barometric error refers to the variation in a clock’s rate caused by changes in air pressure. The barometric error is caused by the fact that the air pressure affects the buoyancy of the pendulum bob.

What is the name of the type of pendulum that uses a jar of mercury to counter the effects of temperature changes?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Mercurial pendulum

Correct Answer Explanation: The mercurial pendulum, commonly used in astronomical clocks, uses a jar of mercury to counter the effects of temperature changes. The mercury expands and contracts with temperature, which changes the position of the pendulum bob. This helps to keep the pendulum’s period constant, even when the temperature changes.

What is the name of the type of pendulum that uses alternating brass and steel rods to compensate for temperature variations?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Mercurial pendulum

Correct Answer Explanation: Harrison’s gridiron pendulum, with its alternating brass and steel rods, compensates for temperature variations by keeping the bob at the same height. When the temperature increases, the brass rods expand more than the steel rods, which raises the bob. This is balanced by the fact that the pendulum’s center of gravity moves downwards.

What is the name of the excess of the time of vibration in a circular arc over that in the cycloidal one belonging to the same length of pendulum?

• Circular error
• Barometric error
• Temperature error
• Gravity error

Correct Answer Explanation: The circular error refers to the excess of the time of vibration in a circular arc over that in the cycloidal one belonging to the same length of pendulum. The circular error is caused by the fact that the pendulum does not swing in a perfect cycloidal arc.

What is the name of a simple meridian dial that can be created by fixing a plate with a vertical slit facing south on a horizontal stone slab, marking the line of brightness at solar noon?

• Dipleidoscope
• Meridian dial
• Solar dial
• Sun dial

Correct Answer Explanation: A meridian dial is a simple device that can be used to determine solar noon. It is created by fixing a plate with a vertical slit facing south on a horizontal stone slab. The line of brightness that is cast through the slit at solar noon is marked on the slab. This line then represents the meridian.

What is the name of the device that utilizes three small plates of glass to produce a single image of the sun at solar noon, acting as a meridian instrument?

• Dipleidoscope
• Meridian dial
• Solar dial
• Sun dial

Correct Answer Explanation: The Dipleidoscope, invented by J.M. Bloxam, utilizes three small plates of glass to produce a single image of the sun at solar noon, acting as a meridian instrument. The Dipleidoscope is a more accurate and precise instrument than the meridian dial.

What is the name of the time that is measured by the apparent motion of the stars?

• Sidereal time
• Solar time
• Mean time
• Equation of time

Correct Answer Explanation: Sidereal time is the time that is measured by the apparent motion of the stars. Sidereal time is a fundamental concept in astronomy and is used to track the positions of stars and other celestial objects.

What is the name of the time that is measured by the apparent motion of the sun?

• Sidereal time
• Solar time
• Mean time
• Equation of time

Correct Answer Explanation: Solar time is the time that is measured by the apparent motion of the sun. Solar time is the time that we use in our everyday lives.

What is the name of the average length of all the solar days in the year?

• Sidereal time
• Solar time
• Mean time
• Equation of time

Correct Answer Explanation: Mean time is the average length of all the solar days in the year. Mean time is a more accurate and consistent measure of time than solar time.

What is the name of a pair of revolving hollow arms driven by water outflow, used to power the great equatorial telescope at Greenwich?

• Conical pendulum
• Barker’s mill
• Fan fly
• Flywheel

Correct Answer Explanation: The great equatorial telescope at Greenwich utilizes a Barker’s mill, a pair of revolving hollow arms, driven by water outflow, to power the clock. The Barker’s mill is a simple and effective device that can be used to generate power from a water source.

What is the name of a pair of weighted arms attached to a revolving vertical axis by horizontal hinges, which regulate velocity more completely than a fly wheel?

• Conical pendulum
• Barker’s mill
• Fan fly
• Flywheel

Correct Answer Explanation: The conical pendulum, used to turn reflectors in revolving lighthouses, involves weighted arms attached to a revolving vertical axis that fly farther out as they go. The conical pendulum is a more accurate and reliable device than the fly wheel.

What is the name of the time that is measured by one absolute rotation of the earth, or the time between two successive passages of the same star over any given meridian?

• Sidereal day
• Solar day
• Mean time
• Equation of time

Correct Answer Explanation: A sidereal day is one absolute rotation of the earth, or the time between two successive passages of the same star over any given meridian. A sidereal day is approximately 3 minutes and 56 seconds shorter than a solar day.

What is the name of the interval between two successive transits of the middle of the sun over the meridian?

• Sidereal day
• Solar day
• Mean time
• Equation of time

Correct Answer Explanation: A solar day is the interval between two successive transits of the middle of the sun over the meridian. A solar day is slightly longer than a sidereal day because the Earth is constantly moving in its orbit around the Sun.

What is the name of the mechanism in a clock that releases a tooth of the scapewheel at each vibration of the pendulum?

• Pendulum
• Escapement
• Fan fly
• Flywheel

Correct Answer Explanation: The escapement is the mechanism in a clock that releases a tooth of the scapewheel at each vibration of the pendulum. The escapement is a key component of a clock’s timekeeping mechanism.

What is the name of an escapement in which the scapewheel stops momentarily after releasing a tooth?

• Anchor escapement
• Crown-wheel escapement
• Recoil escapement

Correct Answer Explanation: The dead escapement is an escapement in which the scapewheel stops momentarily after releasing a tooth. This allows the pendulum to swing freely without being affected by the recoil of the scapewheel.

What is the name of an escapement in which the scapewheel recoils slightly after releasing a tooth?

• Anchor escapement
• Crown-wheel escapement
• Recoil escapement

Correct Answer Explanation: The recoil escapement is an escapement in which the scapewheel recoils slightly after releasing a tooth. The recoil escapement is a less accurate type of escapement than the dead escapement.

What is the name of the type of escapement that is a compromise between the recoil and dead escapements?

• Anchor escapement
• Crown-wheel escapement

Correct Answer Explanation: The half-dead escapement is a compromise between the recoil and dead escapements, offering a more stable rate in large clocks. The half-dead escapement is less accurate than the dead escapement but more stable than the recoil escapement.

What is the name of the type of pendulum that uses a single zinc tube for compensation?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Zinc and steel pendulum

Correct Answer: Zinc and steel pendulum

Correct Answer Explanation: The zinc and steel pendulum, which replaced the gridiron pendulum, uses a single zinc tube for compensation. The zinc tube expands and contracts with temperature, which changes the position of the pendulum bob. This helps to keep the pendulum’s period constant, even when the temperature changes.

What is the name of the type of pendulum compensation that uses a brass and iron bar brazed together that bends upwards with heat, adjusting the pendulum’s center of oscillation?

• Compound bar compensation
• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The compound bar compensation, which uses a brass and iron bar brazed together, bends upwards with heat, adjusting the pendulum’s center of oscillation. The brass expands more than the iron with heat, and so the bar bends upwards. This helps to keep the pendulum’s period constant, even when the temperature changes.

What is the name of the type of pendulum compensation that uses a magnet to compensate for barometric pressure changes?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Greenwich sidereal clock

Correct Answer Explanation: The normal sidereal clock at Greenwich has a zinc pendulum and a barometric compensation system using a magnet. The magnet is attracted to a small iron weight on the pendulum rod. As the air pressure changes, the buoyancy of the pendulum bob changes, and the magnet adjusts the position of the iron weight to compensate for the change in buoyancy.

What is the name of the type of pendulum that is fully compensated for temperature and barometric variations?

• Westminster clock
• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The Westminster clock, designed by Lord Grimthorpe, utilizes a double-barrelled crab mechanism for its striking mechanism and a heavy pendulum that is fully compensated for temperature and barometric variations. The pendulum is made of zinc and steel and has a barometric compensation system that uses a magnet.

What is the name of the largest bell in England?

• Great Paul
• Big Ben
• Great Tom
• St. Paul’s bell

Correct Answer Explanation: The Great Paul bell, housed in St. Paul’s Cathedral, is the largest bell in England. Great Paul weighs over 17 tons and was cast in 1881.

What is the best bell metal for making bells?

• Copper and tin
• Iron and tin
• Steel
• Bronze

Correct Answer Explanation: The best bell metal is a combination of copper and tin, with the exact proportions varying slightly depending on the bell’s size and tone. The tin gives the bell its hardness and resonance, while the copper gives it its strength and durability.

What is the name of the metal that is used for the bobs of large clocks?

• Iron
• Steel
• Copper

Correct Answer Explanation: Lead bobs are preferred for large clocks due to their high specific gravity, making them less resisted by the air. Lead is also a very dense metal, which helps to give the pendulum a good momentum.

What is the name of the material that is superior to glass for mercurial pendulums?

• Iron
• Steel
• Cast iron
• Copper

Correct Answer Explanation: Cast iron jars are superior to glass for mercurial pendulums due to their durability, ease of construction, and ability to withstand heating to remove air bubbles. Cast iron is also a good conductor of heat, which helps to ensure that the mercury in the jar is at the same temperature as the surrounding air.

What is the name of the type of pendulum that is used in astronomical clocks?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Mercurial pendulum

Correct Answer Explanation: The mercurial pendulum, commonly used in astronomical clocks, uses a jar of mercury to counter the effects of temperature changes. The mercury expands and contracts with temperature, which changes the position of the pendulum bob. This helps to keep the pendulum’s period constant, even when the temperature changes.

What is the name of the type of pendulum that is used in large clocks?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: Lead bobs are preferred for large clocks due to their high specific gravity, making them less resisted by the air. Lead is also a very dense metal, which helps to give the pendulum a good momentum.

What is the name of the type of pendulum that is used in the Westminster clock?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Zinc and steel pendulum

Correct Answer: Zinc and steel pendulum

Correct Answer Explanation: The Westminster clock, designed by Lord Grimthorpe, utilizes a double-barrelled crab mechanism for its striking mechanism and a heavy pendulum that is fully compensated for temperature and barometric variations. The pendulum is made of zinc and steel and has a barometric compensation system that uses a magnet.

What is the name of the type of pendulum that is used in the Greenwich sidereal clock?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Zinc and steel pendulum

Correct Answer: Zinc and steel pendulum

Correct Answer Explanation: The normal sidereal clock at Greenwich has a zinc pendulum and a barometric compensation system using a magnet. The magnet is attracted to a small iron weight on the pendulum rod. As the air pressure changes, the buoyancy of the pendulum bob changes, and the magnet adjusts the position of the iron weight to compensate for the change in buoyancy.

What is the name of the type of pendulum that is used in the St. Peter’s Church in St. Albans?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The pendulum at St. Peter’s Church in St. Albans weighs 9 cwt. It is a large pendulum and therefore uses a lead bob.

What is the name of the type of pendulum that is used in the St. Nicolas’s Church in Bristol?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The pendulum at St. Nicolas’s Church in Bristol weighs 12 cwt. It is a large pendulum and therefore uses a lead bob.

What is the name of the type of pendulum that is used in the Westminster clock?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Zinc and steel pendulum

Correct Answer: Zinc and steel pendulum

Correct Answer Explanation: The Westminster clock, designed by Lord Grimthorpe, utilizes a double-barrelled crab mechanism for its striking mechanism and a heavy pendulum that is fully compensated for temperature and barometric variations. The pendulum is made of zinc and steel and has a barometric compensation system that uses a magnet.

What is the name of the type of pendulum that is used in the Greenwich sidereal clock?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Zinc and steel pendulum

Correct Answer: Zinc and steel pendulum

Correct Answer Explanation: The normal sidereal clock at Greenwich has a zinc pendulum and a barometric compensation system using a magnet. The magnet is attracted to a small iron weight on the pendulum rod. As the air pressure changes, the buoyancy of the pendulum bob changes, and the magnet adjusts the position of the iron weight to compensate for the change in buoyancy.

What is the name of the type of pendulum that is used in the St. Peter’s Church in St. Albans?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The pendulum at St. Peter’s Church in St. Albans weighs 9 cwt. It is a large pendulum and therefore uses a lead bob.

What is the name of the type of pendulum that is used in the St. Nicolas’s Church in Bristol?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The pendulum at St. Nicolas’s Church in Bristol weighs 12 cwt. It is a large pendulum and therefore uses a lead bob.

What is the name of the type of pendulum that is used in the Westminster clock?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Zinc and steel pendulum

Correct Answer: Zinc and steel pendulum

Correct Answer Explanation: The Westminster clock, designed by Lord Grimthorpe, utilizes a double-barrelled crab mechanism for its striking mechanism and a heavy pendulum that is fully compensated for temperature and barometric variations. The pendulum is made of zinc and steel and has a barometric compensation system that uses a magnet.

What is the name of the type of pendulum that is used in the Greenwich sidereal clock?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Zinc and steel pendulum

Correct Answer: Zinc and steel pendulum

Correct Answer Explanation: The normal sidereal clock at Greenwich has a zinc pendulum and a barometric compensation system using a magnet. The magnet is attracted to a small iron weight on the pendulum rod. As the air pressure changes, the buoyancy of the pendulum bob changes, and the magnet adjusts the position of the iron weight to compensate for the change in buoyancy.

What is the name of the type of pendulum that is used in the St. Peter’s Church in St. Albans?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The pendulum at St. Peter’s Church in St. Albans weighs 9 cwt. It is a large pendulum and therefore uses a lead bob.

What is the name of the type of pendulum that is used in the St. Nicolas’s Church in Bristol?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The pendulum at St. Nicolas’s Church in Bristol weighs 12 cwt. It is a large pendulum and therefore uses a lead bob.

What is the name of the type of pendulum that is used in the Westminster clock?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Zinc and steel pendulum

Correct Answer: Zinc and steel pendulum

Correct Answer Explanation: The Westminster clock, designed by Lord Grimthorpe, utilizes a double-barrelled crab mechanism for its striking mechanism and a heavy pendulum that is fully compensated for temperature and barometric variations. The pendulum is made of zinc and steel and has a barometric compensation system that uses a magnet.

What is the name of the type of pendulum that is used in the Greenwich sidereal clock?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Zinc and steel pendulum

Correct Answer: Zinc and steel pendulum

Correct Answer Explanation: The normal sidereal clock at Greenwich has a zinc pendulum and a barometric compensation system using a magnet. The magnet is attracted to a small iron weight on the pendulum rod. As the air pressure changes, the buoyancy of the pendulum bob changes, and the magnet adjusts the position of the iron weight to compensate for the change in buoyancy.

What is the name of the type of pendulum that is used in the St. Peter’s Church in St. Albans?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The pendulum at St. Peter’s Church in St. Albans weighs 9 cwt. It is a large pendulum and therefore uses a lead bob.

What is the name of the type of pendulum that is used in the St. Nicolas’s Church in Bristol?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The pendulum at St. Nicolas’s Church in Bristol weighs 12 cwt. It is a large pendulum and therefore uses a lead bob.

What is the name of the type of pendulum that is used in the Westminster clock?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Zinc and steel pendulum

Correct Answer: Zinc and steel pendulum

Correct Answer Explanation: The Westminster clock, designed by Lord Grimthorpe, utilizes a double-barrelled crab mechanism for its striking mechanism and a heavy pendulum that is fully compensated for temperature and barometric variations. The pendulum is made of zinc and steel and has a barometric compensation system that uses a magnet.

What is the name of the type of pendulum that is used in the Greenwich sidereal clock?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Zinc and steel pendulum

Correct Answer: Zinc and steel pendulum

Correct Answer Explanation: The normal sidereal clock at Greenwich has a zinc pendulum and a barometric compensation system using a magnet. The magnet is attracted to a small iron weight on the pendulum rod. As the air pressure changes, the buoyancy of the pendulum bob changes, and the magnet adjusts the position of the iron weight to compensate for the change in buoyancy.

What is the name of the type of pendulum that is used in the St. Peter’s Church in St. Albans?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The pendulum at St. Peter’s Church in St. Albans weighs 9 cwt. It is a large pendulum and therefore uses a lead bob.

What is the name of the type of pendulum that is used in the St. Nicolas’s Church in Bristol?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The pendulum at St. Nicolas’s Church in Bristol weighs 12 cwt. It is a large pendulum and therefore uses a lead bob.

What is the name of the type of pendulum that is used in the Westminster clock?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Zinc and steel pendulum

Correct Answer: Zinc and steel pendulum

Correct Answer Explanation: The Westminster clock, designed by Lord Grimthorpe, utilizes a double-barrelled crab mechanism for its striking mechanism and a heavy pendulum that is fully compensated for temperature and barometric variations. The pendulum is made of zinc and steel and has a barometric compensation system that uses a magnet.

What is the name of the type of pendulum that is used in the Greenwich sidereal clock?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum
• Zinc and steel pendulum

Correct Answer: Zinc and steel pendulum

Correct Answer Explanation: The normal sidereal clock at Greenwich has a zinc pendulum and a barometric compensation system using a magnet. The magnet is attracted to a small iron weight on the pendulum rod. As the air pressure changes, the buoyancy of the pendulum bob changes, and the magnet adjusts the position of the iron weight to compensate for the change in buoyancy.

What is the name of the type of pendulum that is used in the St. Peter’s Church in St. Albans?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The pendulum at St. Peter’s Church in St. Albans weighs 9 cwt. It is a large pendulum and therefore uses a lead bob.

What is the name of the type of pendulum that is used in the St. Nicolas’s Church in Bristol?

• Harrison’s gridiron pendulum
• Loseby’s isochronal spring
• Compensated pendulum

Correct Answer Explanation: The pendulum at St. Nicolas’s Church in Bristol weighs 12 cwt. It is a large pendulum and therefore uses a lead bob.

How much shorter is a sidereal day than a solar day?

• 3 minutes and 56 seconds
• 4 minutes and 48 seconds
• 5 minutes and 12 seconds
• 6 minutes and 24 seconds

Correct Answer: 3 minutes and 56 seconds

Correct Answer Explanation: A sidereal day is one absolute rotation of the earth, or the time between two successive passages of the same star over any given meridian. A sidereal day is approximately 3 minutes and 56 seconds shorter than a solar day.

What is the length of an equinoctial year?

• 365 days, 5 hours, 48 minutes, 49.12 seconds
• 365 days, 6 hours, 52 minutes, 31.12 seconds
• 365 days, 7 hours, 2 minutes, 17.21 seconds
• 365 days, 8 hours, 23 minutes, 54.46 seconds

Correct Answer: 365 days, 5 hours, 48 minutes, 49.12 seconds

Correct Answer Explanation: The equinoctial year is the time it takes for the Earth to complete one orbit around the Sun, measured from one vernal equinox to the next. It is approximately 365 days, 5 hours, 48 minutes, 49.12 seconds.

How much does a steel rod expand for every 1,000 degrees Fahrenheit of heat?

• 0.0064
• 0.0128
• 0.0256
• 0.0512

Correct Answer Explanation: Steel expands by approximately 0.0064 inches per 1,000 degrees Fahrenheit of heat. This is why it is important to use materials that have different thermal expansion coefficients when constructing compensated pendulums.

How much does a zinc rod expand for every 1,000 degrees Fahrenheit of heat?

• 0.0064
• 0.016
• 0.0256
• 0.0512

Correct Answer Explanation: Zinc expands by approximately 0.016 inches per 1,000 degrees Fahrenheit of heat. Zinc expands more than steel, which makes it useful for constructing compensated pendulums.

How much does a lead rod expand for every 1,000 degrees Fahrenheit of heat?

• 0.0064
• 0.016
• 0.0165
• 0.0512

Correct Answer Explanation: Lead expands by approximately 0.0165 inches per 1,000 degrees Fahrenheit of heat. Lead expands more than steel and zinc, which makes it a good material for constructing some types of compensated pendulums.

How much does white deal expand for every 1,000 degrees Fahrenheit of heat?

• 0.0023
• 0.016
• 0.0165
• 0.0512

Correct Answer Explanation: White deal expands by approximately 0.0023 inches per 1,000 degrees Fahrenheit of heat. White deal is a type of wood that is commonly used in construction. It is important to consider the thermal expansion coefficient of wood when designing structures.

What is the specific gravity of mercury?

• 13.6
• 10.5
• 7.85
• 2.7

Correct Answer Explanation: The specific gravity of mercury is 13.6, meaning that a cubic inch of mercury weighs approximately half a pound. This makes mercury a very dense material, which makes it useful for constructing mercurial pendulums.

How much does the Westminster pendulum weigh?

• 700 lbs
• 1,000 lbs
• 1,400 lbs
• 2,100 lbs

Correct Answer Explanation: The Westminster pendulum weighs 700 lbs. It is a very heavy pendulum, which helps to give it a good momentum.

How much does the St. Peter’s pendulum weigh?

• 9 cwt
• 12 cwt
• 15 cwt
• 18 cwt

Correct Answer Explanation: The pendulum at St. Peter’s Church in St. Albans weighs 9 cwt. It is a large pendulum and therefore uses a lead bob.

How much does the St. Nicolas’s pendulum weigh?

• 9 cwt
• 12 cwt
• 15 cwt
• 18 cwt

Correct Answer Explanation: The pendulum at St. Nicolas’s Church in Bristol weighs 12 cwt. It is a large pendulum and therefore uses a lead bob.

How much can a clock pendulum gain in a day if it is put into a vacuum?

• 13 seconds
• 26 seconds
• 39 seconds
• 52 seconds

Correct Answer Explanation: A clock pendulum may gain nearly 13 sec. a day by being put into a vacuum. This is because the air pressure affects the buoyancy of the pendulum bob. When the pendulum is in a vacuum, there is no air pressure to resist the bob, and so the pendulum swings faster.

What is the arc of a clock pendulum that can neutralize the barometric error?

• 1° 45′
• 2° 45′
• 3° 45′
• 4° 45′

Correct Answer Explanation: The circular error can neutralize the barometric error in a clock with an arc of 2° 45′. This is because the circular error is caused by the fact that the pendulum does not swing in a perfect cycloidal arc.

What is the name of the type of compensation that is used in the Greenwich sidereal clock?

• Zinc and steel compensation
• Compound bar compensation
• Mercurial compensation
• Magnetic compensation

Correct Answer Explanation: The normal sidereal clock at Greenwich has a zinc pendulum and a barometric compensation system using a magnet. The magnet is attracted to a small iron weight on the pendulum rod. As the air pressure changes, the buoyancy of the pendulum bob changes, and the magnet adjusts the position of the iron weight to compensate for the change in buoyancy.

What is the average variation of the Westminster clock per week?

• 1 second
• 2 seconds
• 3 seconds
• 4 seconds

Correct Answer Explanation: The Westminster clock only varies 1 sec. a week on average. This is a testament to the high quality of its construction and the accuracy of its timekeeping mechanism.

What is the name of the measure of a body’s resistance to rotational acceleration?

• Moment of inertia
• Center of oscillation
• Center of percussion
• Circular error

Correct Answer Explanation: The moment of inertia is a measure of a body’s resistance to rotational acceleration. The moment of inertia depends on the mass of the body and the distribution of the mass around the axis of rotation.

What is the name of the ancient timekeeping device that uses the flow of water to measure time?

• Clepsydra
• Sundial
• Hourglass
• Water clock

Correct Answer Explanation: A clepsydra, also known as a water clock, is an ancient timekeeping device that uses the flow of water to measure time. The clepsydra was used in ancient Egypt, Greece, and Rome.

What is the name of the ancient timekeeping device that uses the shadow cast by the sun to measure time?

• Clepsydra
• Sundial
• Hourglass
• Water clock