As an amateur clock repairer, I’ve been hunting for a good glossary of clock part names. Then one day I found clock conservator Matthew Read talked about one in his How to repair pendulum clocks – LIVESTREAM #005, where at about 1:26:00 he mentions a 17th or 18th Century work by William Derham. One of the live-stream attendees found the title of that work.

What follows is Chapter 1 of “The Artificial Clockmaker” by William Derham, published in 1734, courtesy of Google Books. This chapter gives the then-current names and descriptions of the parts of a mechanical clock. Many of these names have survived into the 21st Century. Where necessary I’ve added annotations in brackets.

Chap. I. Of the Terms of Art, or Names by which the Parts of an Automaton are called.

It is necessary that I should show the meaning of the Terms which Clock-makers use, that Gentlemen and others, unskilful in the Art, may know how to express themselves properly, in speaking; and also understand what I shall say in the following Book.

I shall not trouble the Reader with a recital of every Name that doth occur, but only such as I shall have occasion to use in the following Discourse, and some few others that offer themselves, upon a transient View of a Piece of Work.

I begin with the more general Terms: As, the Frame; which is that which contains the Wheels, and the rest of the Work. The Pillars and Plates, are what it chiefly consists of. [The Front Plate is, from the clock’s point of view, the front of the clock, and usually holds the hour hand and minute hand. The Back Plate is at the back of the clock. The Pillars hold the plates together.]

Next for the Main-Spring, and its Appurtenances. That which the Spring lies in, is the Spring-Box: that which the Spring laps about, in the Middle of the Spring Box, is the Spring-Arbour [Arbor, the axle]; to which the Spring is hooked at one end [of the spring]. At the Top of the Spring-Arbour, is the Endless-Screw [Worm Gear], and its Wheel; but in Spring-Clocks it is a Ratchet-Wheel with its Click (that stops it).

That which the main Spring draweth, and about which the Chain or String [Gut Line or Cat Gut] is wrapped, and, which is commonly taper [that is, conical], is the Fusy [Fusee]. In larger work, going with Weights, where it is cylindrical, it is called the Barrel: the small Teeth at the Bottom of the Fusy [Fusee], or Barrel, that stop it in winding up, is the Ratchet. That which stops it when wound up, and is for that end driven up by the String, is the Garde-gut [Winding-Stop].

The Parts of a Wheel [that is, a gear] are, the Hoop, or Rim; the Teeth; the Cross; and the Collet, or piece of Brass, soddered [soldered] on the Arbour [Arbor], or Spindle, on which the Wheel is rivitted.

A Pinion is that little Wheel, which plays [meshes] in the Teeth of the Wheel. Its Teeth (which are commonly 4, 5, 6, 8, etc.) are called Leves [Leaves], not Teeth. [sometimes Pinions are formed from wires, and are called Lantern Pinions.]

The Ends of the Spindle, are called Pivots: the Holes in which they run, Pivot-holes.

The guttered Wheel, with Iron Spikes at the bottom [Sprockets for a chain driven clock, I assume], in which the Line [Chain or String] of ordinary House-Clocks doth run, is called the Pully [Pulley].

I need not speak of the Dial-Plate, the Hand[s], Screws, Wedges, Stops, etc. [Also, Tapered-Pins are often used to hold parts together. There are various Springs which apply pressure to Levers or Clicks.]

The much for general Names, which are common to all Parts of a Movement [now, Movement is used to refer to the entirety of the brass, steel, or iron works, which are mounted in a clock Case].

The most usual Movements [Trains] are Watches and Clocks [now, the Going-Train or Time-Train runs the hands; the Striking-Train strikes the hours; the Chiming-Train plays music at various times]. Watches strictly taken, are all such Movements as shew the Parts of Time: and Clocks are such as publish it, by striking on a Bell, etc. But commonly the Name of Watches is appropriated to such as are carried in the Pocket; and that of Clocks to the larger Movements, whether they strike the Hour or no. As for Watches which strike the Hour, they are called Pocket-Clocks [I’m not quite sure what the modern term is. Perhaps Striking- or Musical-Pocket-Watches].

The Parts of a Movement, which I shall consider, are the Watch- [Going-Train; Time-Train], and the Clock-Parts [Striking-Train].

The Watch-Part [Going-Train; Time-Train] of a Movement is that which serveth to the measuring the hours. In which the first thing I shall consider is the Balance [Now the Escapement, which has many different styles and associated terms]; whose parts are, the Rim, which is the circular part of it; the Verge, is its Spindle; to which belong the two Pallets, or Leves [Leaves] which play in [mesh with] the Teeth of the Crown-Wheel [or Escape-Wheel, depending on the style of Escapement]; in Pocket Watches, that strong Stud in which the lower Pivot of the Verge plays [meshes], and in the middle of which one Pivot of the Balance-Wheel plays, is called the Pottance vulgarly [I’m not sure what he’s talking about here], I suppose for Potence (it being strong) or Portance, as Dr. Hook [inventor Dr. Robert Hooke] calls it in his Helioscop. p. 10. The bottom of this is called the Foot; the middle part (in which the Pivot of the Balance-wheel turns) is called the Nose; the upper-part, the Shoulder of the Portance. The piece which covers the Balance, and in which the upper Pivot of the Balance plays, is the Cock. The small Spring in the new Pocket-Watches underneath the Balance, is the Regulator or Pendulum-Spring.

The parts of a Pendulum are, the Verge, Pallets, and Cocks, as before. The Ball [I haven’t seen this term used] in long Pendulums, the Bob in short ones, is the Weight at the bottom. The Rod, or Wire, is plain [the Rod is fastened to the Bob]. The terms peculular to the Royal Swing [perhaps an old term for a Seconds-Pendulum, whose swing is one second each way], are the Pads, which are the Pallets in others, and are fixed on the Arbor. The Fork [perhaps the Suspension-Spring?] is also fixed to the Arbor, and about 6 inches below, catcheth hold on the Rod, at a flat piece of Brass, called the Flatt [I haven’t heard this term], in which the lower end of the Spring is fastened.

The Names of the Wheels next follow. The Crown-Wheel in small pieces [small clocks], and Swing-Wheel in Royal Pendulums, is that Wheel which drives the Balance, or Pendulum.

The Contrate-Wheel, is that Wheel in Pocket-Watches, and others, which is next to the Crown-Wheel, whose Teeth and Hoop lie contrary to those of other Wheels; whence it hath its Name.

The Great-Wheel, or First-Wheel, is that which the Fusy [Fusee], etc. immediately driveth. Next it, are the Second-Wheel, Third-Wheel, etc. [see more detail below.]

[A Train now refers to a set of meshed wheels (Great-Wheel, Second-Wheel, etc.) which convey power from a Main-Spring or Weight to some destination, such as the Escape-Wheel or the Fan]

Next followeth the Work between the Frame and Dial-Plate. And first, is the Pinion of Report [I haven’t heard this term before]; which is that Pinion, which is commonly fixed on the Arbor of the Great-Wheel, and in old Watches [that is, Time-Trains] used to have commonly but four Leaves; which driveth the Dial-Wheel, and this carrieth about the Hand.

The last part which I shall speak of is the Clock [the Striking-Train], which is that part which serveth to strike the Hours: In which I shall

First speak of the Great [-Wheel], or First-Wheel; which is that which the Weight or Spring first drives. In 16 or 30 Hour Clocks, this is commonly the Pin-Wheel; in 8 Day Pieces [clocks], the Second Wheel is commonly the Pin-Wheel. This Wheel thus with Pins is called the Striking-Wheel, or Pin-Wheel.

Next to this Striking-Wheel, followeth the Detent-Wheel [Count-Wheel], or Hoop-Wheel, it having a Hoop almost round it, in which is a vacancy [a slot], at which the Clock [Striking-Train] locks. [In Rack-and-Snail clocks, vs. Count-Wheel clocks, the Count-Wheel-related parts are replaced by a number of parts not named in this book.]

The next is the Third- or Fourth-Wheel (according as it is distant from the First-Wheel) called also the Warning-Wheel.

And lastly [in the Striking-Train or Chiming-Train] is the Flying-Pinion, with a Fly or Fan [also called the Governor] to gather Air, and so bridle [reduce] the Rapidity of the Clock’s motion.

Besides these, there are the Pinion of Report, of which before, which driveth round the Locking-Wheel, called also the Count-Wheel, with 11 Notches in it commonly, unequally distant from one another, to make the Clock strike the Hours of 1, 2, 3, etc.

Thus much for the Wheels of the Clock-part [the Striking-Train or Chiming-Train].

Besides which there are the Rasb, or Ratch; which is that sort of Wheel, of twelve large Fangs, that runneth concentrical to the Dial-Wheel, and serveth to lift up the Detents every Hour, and make the Clock strike.

The Detents are those Stops, which by being lifted up, or let fall down, do lock and unlock the Clock [Striking-Train] in Striking. [Possibly the Lift-Lever, Warning-Lever, and Locking-Lever.]

The Hammers strike the Bell: The Hammer-Tails are what the Striking-pins draw back the Hammers by.

Latches are what lift up, and unlock the Work.

Catches are what hold by hooking, or catching hold of.

The Lifting-pieces do lift up, and unlock the Detents, in the Clock [Striking] part.

The Train is the Number of Beats [a tick or a tock] or Vibrations [a tick plus a tock] which the Watch [Going-Train; Time-Train] maketh in an Hour, or any other certain time. [Train now refers to a set of meshed wheels, and BPH or Beats-Per-Hour is one measure of the number of Beats in an hour.]

There are besides these divers [diverse] other Terms which the Clockmakers use in various Sorts of Pieces [clocks], as the Snail [the more common term], or Step-Wheel [?] in Repeating Clocks, the Rack [the lever that drops into the Snail], the Safeguards [?], the several Levers, Lifters, and Detents: But it would be tedious, and it is needless to mention the particulars. [That is, you can read about the names and functions of these parts in books devoted to, for example, repairing a striking clock.]

For the better understanding these Terms of Art, and the Parts of a Clock, I have in Fig. I. represented them to the Eye. In which, two distinct Parts may be observed, the Watch- [Time-Train; Going-Train], and the Clock-Part [Striking-Train or Chiming-Train].

[The remaining few pages of the chapter show how to find the various clock parts in Fig 1. Sadly, the figure is on a folding page, which was not folded out for scanning. I have no access to the original book.]

Featured Image: The title page of "The Artificial Clockmaker" by William Derham, first published in 1734. From Google Books.