Frequently Asked Questions
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Mechanical Clock Features
» What is the purpose of the moon phase clock dial and how do you set it?
In the 18th century dials with an arch to the top were introduced allowing clockmakers to accommodate a secondary moon phase dial. At that time knowing when to expect a full moon was valuable for people who had to travel, or worked at night. It was also valuable to people who worked at sea because of the influence of the moon on the sea tides.
Clockmakers re-created the progress of the moon from phase to phase during the lunar month of 29½ days. The moon was generally set on a background of the night sky or a landscape.
To set a moon dial on a new clock, apply slight pressure with your fingers to the front of the dial and rotate it until the full moon is directly below the numeral 15.* Using an almanac or calendar, determine the date of the last full moon. Count the number of days past the last or before the next full moon. Turn the moon dial clockwise or counter clockwise for every day past or before the full moon. One click of the moon dial equals one day.The moon dial is now set and will indicate the proper moon phases as long as the clock operates continuously. If the clock stops for more than 24 hours, the moon dial will also stop and will require resetting when the clock is started again.
*Please note that it is not possible to rotate the moon dial when it is engaged with the clock mechanism. If this is the case wait for an hour or so before making the adjustment.
» What is the origin of the popular chime melodies played by clock mechanisms?
Chime melodies and bell strike mechanisms were first introduced to public and then domestic clocks so that the time could be broadcast to a community or a household.
The world's most famous chime is the Westminster chime associated with “Big Ben”, the bell in the clock tower of the Houses of Parliament in London. The melody evolved from a phrase from the fifth bar of Handel's Messiah, 'I know that my redeemer liveth' and was originally played by the clock of Great St. Mary's Church in Cambridge, England.
In 1764 St. Michael's Church was built in Charleston, South Carolina USA. The chime from the clock became known as the St. Michael’s Chime. The bells used were cast in London.
The famous Whittington Chime is derived from the Church of St. Mary's le Bow in Cheap Side, London. Legend has it that Dick Whittington, running away from ill treatment as a house waif, seemed to hear the chimes say "Turn again Whittington Lord Mayor of London Town". He turned back and later served three terms as London's Lord Mayor.
Typically chimes are played on each quarter of the hour, the melody building until it is fully played on the hour followed by the clock striking the actual time.
» How does a pendulum work and how do you adjust its beat?
The principle of using the consistent rate of oscillation of the swing of a pendulum to regulate a clock was described by Galileo in the 16th century. However, the first such timepiece was made in the Hague by Soloman Coster in 1656 to a design by Christian Huygens the Dutch physicist.
A clock movement consists of a system of brass and steel wheels and gears, known as the gear train, and usually housed between two brass plates. The mechanism is typically powered by springs or weights. The rate that the power is released is controlled by the escapement mechanism. For pendulum clocks the escapement mechanism is controlled by the constant swing of the pendulum.
The anchor escapement illustrated was developed by William Clement in 1671 and became the standard for long-cases and bracket clocks. The “anchor” at the top rocks with the swing of the pendulum, engaging and disengaging with the escapement wheel to allow it to progress one tooth at a time.
This action gives the familiar “tick-tock” sound of the mechanical clock. The clock is said to be in beat when this sound is even, that is the anchor is engaging with equal depth and pressure on each side. On old clocks this adjustment had to be made by a clockmaker adjusting the position of the “anchor”. However, on modern movements this adjustment is automatic or can easily be made when setting up a clock. Refer to the product instructions for further guidance.
To adjust the timekeeping of a pendulum clock move the pendulum bob (the disc at the bottom of the rod) up or down by screwing up or down the rating nut below the bob.. “Shorter” pendulums run faster. Refer to product instruction for a guide to the amount of adjustment.
Clock Maintenance
» Can I change the volume/sound of the chimes?
The sound can be slightly adjusted by moving the hammers closer or further away from the chime rods or bells. This is achieved by bending the rods either by using finger pressure or suitable pliers. This is also the method of adjusting the hammer positions if they are too close or they are lifting but not dropping onto the rods or bells. The ideal position is a 2mm gap between the hammer head and the rods or bells.
» The minute hand does not exactly point to each quarter when the clock chimes,
can I make an adjustment?
Yes, remove the minute hand by releasing the centre nut or taper pin securing it in position. The hand is mounted onto a brass collar. By rotating this collar the hand can be re-positioned. Holding the collar with pliers or from its centre using a square section of metal (square section bradawls can be used for this purpose) rotate the hand. Re-fit the hand to the movement to check the new position and repeat as necessary.
» The hour hand points to the incorrect hour when the clock strikes the time, can I make an adjustment?
Yes, simply use finger pressure to push the hour hand to the hour struck. This will not cause any damage to the clock mechanism. Once this has been done reset the time by rotating the minute hand.
» How often should a new clock movement be cleaned or serviced?
New clock movements need very little attention. However, we recommend a thorough cleaning and oiling every five to ten years (use synthetic clock oil 859). In climate zones with very dry or salty air and/or extremely hot or cold temperatures, more frequent maintenance may be advisable. Comitti can undertake this work when required.
Delivery
» What are the delivery lead times?
We do not maintain inventory information on this website. However, most items are held in stock in our warehouse. Stock items are typically delivered using a next day service. If out of stock we will notify you when we receive your order.
You can request delivery information by calling our sales department on + 44 (0) 1277 367670 or you can use the “Enquire about this product” button when viewing product detail for a selected model. Longcase floor clocks are typically finished to order because of customer specified finishes and dial options. The lead time for these models is 3/5 weeks.
» What are the delivery costs?
We offer free delivery on all retail orders to be delivered within the UK mainland. In the case of weight driven floor clocks or wall clocks and speciality skeleton clocks we offer a delivery and set up service using our own staff and vehicles at no extra charge. Deliveries using our own home delivery service are organised by appointment on an am or pm basis Tuesday to Thursday.
Please contact our sales department on +44 (0) 1277 367670 for details or for overseas delivery quotations.
Weather Instruments Features
» What is an aneroid barometer?
The aneroid barometer is a pressure gauge that measures changes in atmospheric pressure. Good quality movements are temperature compensated to achieve greater accuracy. Because changes in pressure influence weather conditions, barometers are used to make weather forecasts.
» Where is the best place to locate a barometer?
The barometer can be located anywhere in your home but it is recommended that it is not positioned in direct sunlight or near sources of heat.
» How can I adjust my aneroid barometer for altitude?
Barometers are set to read correctly at sea level when they are made. Because atmospheric pressure drops as altitude increases, it is necessary to make compensating adjustments. For every 100 feet (30.48m) in altitude add 0.12 of an inch. To make an adjustment move the black indicator hand by turning the setscrew visible from the back of the movement by the amount required for your altitude.
Alternatively, you can check the correct reading for your area in the UK by visiting the Met Office website: www.metoffice.gov.uk
» How do I read an aneroid barometer?
The rise and fall of atmospheric pressure, rather than the absolute reading, indicates approaching weather conditions. The words ‘Fair, Change, Rain’ etc. cannot therefore be relied upon. The following procedure, carried out morning and evening, will enable you to make a forecast.
a. Tap the instrument lightly to release any latent build up in pressure.
b. Adjust the index hand by rotating the knob in the centre of the glass directly over the black indicator.
c. At the next reading you will notice in which direction, and to what degree, the atmospheric pressure has changed.
A clockwise movement indicates rising pressure and improving weather conditions. An anti-clockwise movement indicates falling pressure and deteriorating conditions. A steady barometer indicates a continuation of prevailing conditions.
Readings obtained on a daily basis indicate conditions that are likely in the next 24-48 hours.
Refer to the product instructions for a more detailed interpretation of pressure changes.
» What is a hygrometer and how is it calibrated?
A hygrometer indicates the moisture in the prevailing surroundings, a useful instrument in the home.
Please note that the hygroscopic element of the modern hygrometer coil declines in accuracy over time. To recalibrate the instrument place the unit on a platform in a vessel that contains water. Place a lid over the top of the vessel and leave it to stand for 6 hours. Immediately when opening the vessel set the hygrometer indicator to 95% by rotating the coil casing visible from the back using a small screwdriver. After a few hours the hygrometer will revert to the correct reading for its surrounding conditions.
Note that if fitted to a barometer the hygrometer should be removed before carrying out this procedure and must not be immersed in the water.
Weather Instrument Maintenance
» How can I re-join the spirit separated in a thermometer?
To re-join the spirit, remove the tube from the scale and place it in a refrigerator. As the reading drops shaking the tube in a downward motion will help to re-join the spirit.
Transporting Barometers
» Is it safe to take a barometer on an aeroplane?
Aneroid barometers travel safely and without restriction on aeroplanes. If they travel in the hold of the plane packed with luggage the pressure reading will drop dramatically but return to the correct reading after landing. However, on balance it is safer for a barometer to be carried as hand luggage to prevent damage due to poor handling.
Mercury barometers are generally not allowed on aeroplanes because of the mercury hazard if the instrument is broken. Some airlines will allow them if they are appropriately packed and have the correct paperwork.
Shipping these instruments by sea-freight also requires special paperwork but this is relatively straight forward. Please contact our sales office for further information.
