The
Linotype typesetting machine (icon ) is a "line casting" machine used in
printingPrinting is a process for reproducing text and image, typically with ink on paper using a printing press. It is often carried out as a large-scale industrial process, and is an essential part of publishing and transaction printing....
. The name of the machine comes from the fact that it produces an entire line of metal
typeType may refer to:In philosophy:*Type–token distinctionIn mathematics:*Type *Type theory, basis for the study of type systems*Type or arity, the number of operands a function takes...
at once, hence a
line-o'-type, a significant improvement over manual typesetting.
The Linotype machine operator enters text on a 90-
character keyboard. The machine assembles
matrices, which are molds for the letter forms, in a line. The assembled line is then cast as a single piece, called a
slug, of
type metalIn printing, type metal refers to the metal alloys used in traditional typefounding and hot metal typesetting. Lead is the main constituent of these alloys...
in a process known as
"hot metal" typesettingIn printing and typography, hot metal typesetting refers to 19th-century technologies for typesetting text in letterpress printing. This method injects molten type metal into a mold that has the shape of one or more glyphs...
. The matrices are then returned to the type magazine from which they came. This allows much faster typesetting and composition than original hand composition in which operators place down one pre-cast metal
letterA letter is a grapheme in an alphabetic system of writing, such as the Greek alphabet and its descendants. Letters compose phonemes and each phoneme represents a phone in the spoken form of the language....
,
punctuation markPunctuation marks are symbols that indicate the structure and organization of written language, as well as intonation and pauses to be observed when reading aloud.In written English, punctuation is vital to disambiguate the meaning of sentences...
or
spaceIn writing, a space is a blank area devoid of content, serving to separate words, letters, numbers, and punctuation. Conventions for interword and intersentence spaces vary among languages, and in some cases the spacing rules are quite complex....
at a time.
The machine revolutionized typesetting and with it especially
newspaperA newspaper is a scheduled publication containing news of current events, informative articles, diverse features and advertising. It usually is printed on relatively inexpensive, low-grade paper such as newsprint. By 2007, there were 6580 daily newspapers in the world selling 395 million copies a...
publishing, making it possible for a relatively small number of operators to
set typeTypesetting is the composition of text by means of types.Typesetting requires the prior process of designing a font and storing it in some manner...
for many pages on a daily basis. Before Mergenthaler's invention of the Linotype in 1884, no
newspaperA newspaper is a scheduled publication containing news of current events, informative articles, diverse features and advertising. It usually is printed on relatively inexpensive, low-grade paper such as newsprint. By 2007, there were 6580 daily newspapers in the world selling 395 million copies a...
in the world had more than eight pages.
Matrices
Each matrix contains the letter form for a single character of a
fontIn typography, a typeface is the artistic representation or interpretation of characters; it is the way the type looks. Each type is designed and there are thousands of different typefaces in existence, with new ones being developed constantly....
of type; i.e., a particular type design in a particular size. The letter form is engraved into one side of the matrix. For sizes up to 14
pointsIn typography, a point is the smallest unit of measure, being a subdivision of the larger pica. It is commonly abbreviated as pt. The point has long been the usual unit for measuring font size and leading and other minute items on a printed page....
, and in some matrices of size 16 to 24 points, the matrix has two letter forms on it, the upright (Roman) and the slanted (
Italic) form of a given character. The machine operator can select which of the two will be cast by operating the
auxiliary rail of the
assembler, or, when setting entire lines of italics, by using the
flap, which was a piece that could be turned under a portion of the first elevator column. This is the origin of the old typesetting terms
upper rail for italic and
lower rail for Roman characters. These terms persisted in phototypesetting technology even though the mechanics of the auxiliary rail do not exist there.
Magazine section
The magazine section is the part of the machine where the matrices are held when not in use, and released as the operator touches keys on the keyboard. The magazine is a flat box with vertical separators that form "channels", one channel for each character in the font. Most main magazines have 90 channels, but those for larger fonts carried only 72 or even 55 channels. The auxiliary magazines used on some machines typically contained 34 channels or, for a magazine carrying larger fonts, 28 channels.
The magazine holds a particular
fontIn typography, a typeface is the artistic representation or interpretation of characters; it is the way the type looks. Each type is designed and there are thousands of different typefaces in existence, with new ones being developed constantly....
of type; i.e., a particular type design in a particular size. If a different size or style was needed, the operator would switch to a different magazine. Many models of the Linotype machine could keep several magazines (as many as four) available at a time. In some of these, the operator could shift to a different magazine by raising or lowering the stack of magazines with a crank. Such machines would not allow mixing fonts within a single line. Others, such as the Model 9, allowed arbitrary mixing of text from up to four magazines within a single line.
Escapement
In a Linotype machine, the term
escapements refers to the mechanisms at the bottom of the magazine that releases matrices one at a time as keys are pressed on the keyboard. There is an escapement for each channel in the magazine.
Maintenance and lubrication
To keep the matrices circulating smoothly throughout the machine, it is necessary that oil not be allowed anywhere near the matrix path. If oil is found in the matrix's path (due to careless maintenance or over-lubrication of nearby parts), it combines with dust, forming a gummy substance that is eventually deposited in the magazine by the matrices. The most common result is that the matrix will not be released from the magazine at its usual speed, and almost always results in a letter or two arriving out of sequence in the assembler — a 'matrix transposition'. When these machines were in heavy use, it was not uncommon for an operator to set type at the rate of over 4000
emsAn em is a unit of measurement in the field of typography, equal to the currently specified point size.The name of em is related to M. Originally the unit was derived from the width of the capital "M" in the given typeface....
per hour (the fastest operators being able to exceed 10,000 ems per hour) so the need for careful lubrication and regular cleaning was essential to keep these machines operating at their full potential.
Keyboard and composing section
In the composing section, the operator enters the text for a line on the keyboard. Each keystroke releases a matrix from the magazine mounted above the keyboard. The matrix travels through channels to the assembler where the matrices are lined up side by side in the order they were released.
When a space is needed, the operator touches the
spaceband lever just to the left of the keyboard. This releases a
spaceband from the spaceband box. Spacebands are stored separately from the matrices because they are too big to fit in the magazine.
Once enough text has been entered for the line, the operator depresses the
casting lever mounted on the front right corner of the keyboard. This lifts the completed line in the assembler into the casting section of the machine and engages the clutch that drives the casting and distribution sections. The operator is now finished with the line; the remaining processing is automatic. While the line is being cast, the operator can continue entering text for the next line.
Keyboard
The keyboard has 90 keys. There is no shift key; uppercase letters have keys separate from the lowercase letters. The arrangement of letters corresponds roughly to letter frequency, with the most frequently used letters on the left.
The first two columns of keys are: e, t, a, o, i, n; and s, h, r, d, l, u. A Linotype operator would often deal with a typing error by running the fingers down these two rows, thus filling out the line with the nonsense words
etaoin shrdluETAOIN SHRDLU is a nonsense phrase that sometimes appeared in print in the days of "hot type" publishing because of a custom of Linotype machine operators. It appeared frequently enough that it became part of the lore of newspapers...
. This is known as a
run down. It is often quicker to cast a bad slug than to hand-correct the line within the assembler. The slug with the run down is removed once it has been cast, or by the proofreader.
The Linotype keyboard has the same alphabet arrangement given twice, once for lower-case letters, the keys in black, on the left side of the keyboard, and once for upper-case letters, the keys in white, located on the right side of the keyboard. The blue keys in the middle are punctuation, digits, small capital letters and fixed width spaces. In proper keyboard operation, an experienced operator's left hand operates only the spaceband key and the left column of keys. The operator's right hand strokes the remaining keys on the entire keyboard.
The keys of the keyboard are connected by vertical pushrods to the escapements. When a key is pressed, the corresponding escapement is actuated, which releases a matrix from the magazine. With one exception, each key corresponds directly to a channel in the standard (
90 channel) magazine. The one exception is the lower-case letter
e: that letter is used so often that the
90 channel magazine actually has 91 channels, with two channels (the leftmost two) both used for the letter
e. Similarly, the
72 channel magazine actually has 73 channels, with the leftmost two being used for lower-case
e. Consecutive keystrokes on the
e key release matrices alternately from the two
e channels in the magazine.
On machines that support multiple magazines, there is a shifting mechanism that controls which magazine is currently connected to the keyboard. In most machines, this is done by raising or lowering the stack of magazines.
Spaceband box
In justified text, the spaces are not fixed width; they expand to make all lines equal in width. In Linotype machines this is done by spacebands. A spaceband consists of two wedges, one similar in size and shape to a type matrix, one with a long tail. The wide part of the wedge is at the bottom of the tail, so pushing the tail up expands the spaceband.
Due to their size, spacebands are not held in the magazine, but in a spaceband box and released one at a time by pressing the spaceband lever at the left edge of the keyboard.
Assembler
Matrices released from the magazine, and spacebands released from the spaceband box, drop down into the assembler. This is a rail that holds the matrices and spacebands, with a jaw on the left end set to the desired line width. When the operator judges that the line is close enough to full, he raises the casting lever on the bottom of the keyboard to
send the line to the casting section of the Linotype machine. The remaining processing for that line is automatic; as soon as the finished line has been transferred to the casting section, the operator can begin composing the next line of text.
Casting section
The casting section receives completed lines from the assembler, and uses these to cast the type slugs that are the product of the Linotype machine. The casting section is automatic: once it is activated by the operator sending a completed line by raising the casting lever, a series of cams and levers move the matrices through the casting section and control the sequence of steps that produce the slug.
The casting material is an alloy of lead (85%), antimony (11%), and tin (4%) , and produces a one-piece casting slug capable of 300,000 impressions before the casting begins to develop deformities and imperfections, and the type must be cast again.
The continuous heating of the molten alloy causes the tin and antimony in the mixture to rise to the top and oxidize along with other impurities into a substance called "dross" which has to be skimmed off. Excessive dross formation leads to the alloy softening as the proportion of lead increases. The mixture must then be assayed and tin and antimony added back (in the form of a specially proportioned alloy) to restore the original strength and properties of the alloy.
Justification
From the assembler, the assembled line moves via the
first elevator to the
justification vise. The vise has two jaws (1 and 2 in the illustration) which are set to the desired line width. The spacebands are now expanded to justify the line. When the line is justified, the matrices fit tightly between the vise jaws, forming a tight seal which will prevent the molten type metal from escaping when the line is cast.
Justification is done by a spring-loaded ram (5) which raises the tails of the spacebands, unless the machine was equipped with a Star Parts automatic hydraulic quadding attachment
If the operator did not assemble enough characters, the line will not justify correctly: even with the spacebands expanded all the way, the matrices are not tight. A safety mechanism in the justification vise detects this and blocks the casting operation. Without such a mechanism, the result would be a
squirt of molten type metal spraying out through the gaps between the matrices, creating a time consuming mess and a possible hazard to the operator. If a squirt did occur, it was generally up to the operator to grab the
hell bucket and catch the flowing lead. It was so called because the bucket would often "go to hell", or melt, while holding the molten lead that was still extremely hot. Also, in conjunction with possible hazards facing an operator, toxic lead fumes should be noted as they were the result of melting the lead ingots for casting.
Mold disk and pot
The justification vise holds the assembled line against the face of the
mold disk. The mold disk has rectangular openings which correspond to the width and thickness of the
slugs (cast lines) to be made.
Mold liners fit into these openings for specific slug dimensions.
Behind the mold disk is the type metal pot, which contains molten
type metalIn printing, type metal refers to the metal alloys used in traditional typefounding and hot metal typesetting. Lead is the main constituent of these alloys...
. A piston in the pot pushes the molten metal down into the pot, which forces the metal through the pot throat and into the mold, forcing it against the faces of the matrices. These have character shapes cut into them, so the result is a cast
slug with the character shapes of the line on its front face. The mold disk is sometimes water-cooled, and often air-cooled with a blower, to carry away the heat of the molten type metal and allow the cast slugs to solidify quickly.
When casting is complete, the mold disk turns three-quarters of a turn counterclockwise to the
ejector and
knife block assembly. The ejector is a rectangular rod that pushes the completed slug from the mold aperture in the mold disk. As it emerges from the mold disk, the slug passes a set of knife edges in the knife block, which trims off any small irregularities in the casting and produces a slug of exactly the desired width and height. From there, the slug drops into the
galley tray which holds the lines in the order in which they were cast.
Distribution mechanism
The most significant innovation in the Linotype machine was that it automated the distribution step; i.e., returning the matrices and space bands back to the correct place in their respective magazines. This is done by the
distributor.
After casting is completed, the matrices are pushed to the
second elevator which raises them to the
distributor at the top of the magazine. The space bands are separated out at this point and are returned to the spaceband box.
The matrices have a pattern of teeth at the top, by which they hang from the
distributor bar. Some of the teeth are cut away; which pattern of teeth is cut away depends on the character on the matrix; i.e., which channel in the magazine it belongs in. Similarly, teeth are cut away along portions of the distributor bar. The bar on the elevator has all teeth, so it will hold any matrix (but not the space bands, which have no teeth at all).
Distributor bar and matrix teeth coding
As the matrices are carried along the distributor bar by the distributor screws, they will hang on only so long as there are teeth to hold them. As soon as the matrix reaches the point where each of its teeth corresponds to a cut-away tooth on the distributor bar, it is no longer supported and will drop into the matrix channel below that point.
The pattern of teeth is essentially a binary code, counting up from the left side of the main magazine. Code 0 (no teeth) is for space bars, which are not carried up to the distributor. Code 1 is skipped (no reason for this is given in the Linotype manual). Codes 2 through 92 are for the 91-channel main magazine, and the codes above that are for the auxiliary magazine, if one is installed on the machine. The widest auxiliary magazine has 34 channels, so its rightmost channel is code 125. Code 126 is unused.
Pi matrices
In typesetting, it is sometimes necessary to use characters that are uncommon or obscure enough that it does not make sense to assign them to a magazine channel. These characters are referred to as
pi characters or
sorts ('pi' in this case refers to an obscure printer's term relating to loose or spilled type). Footnote marks, rarely used fractions, and mathematical symbols are examples of pi characters. In the Linotype machine, a pi matrix has all teeth present (code 127, no teeth cut away) so it will not drop from the distributor bar and will not be released into either the main or the auxiliary magazine. Instead, it travels all the way to the end and into the flexible metal tube called the
pi chute and is then lined up in the
sorts stacker. From the sorts stacker, the machine operator can (manually) pick pi matrices and insert them into the line being assembled as needed.
Operation
The Linotype machine consists of four major sections:
- Magazine
- Keyboard
- Casting mechanism
- Distribution mechanism
The operator interacts with the machine via the keyboard, composing lines of text. The other sections are automatic; they start as soon as a line is completely composed.
Some Linotype machines included a paper tape reader. This allowed the text to be typeset to be supplied over a telegraph line (TeleTypeSetter). It also allowed for several tape perforator operators to prepare paper tape to be processed by a single Linotype machine, essentially decoupling the typing speed of the operators from the operating speed of the Linotype machine.
See also
- Ottmar Mergenthaler
Ottmar Mergenthaler was an inventor who has been called a second Gutenberg because of his invention of the Linotype machine, the first device that could easily and quickly set complete lines of type for use in printing presses...
- Monotype System
The Monotype system is a set of two machines, the Monotype keyboard and the Monotype caster, which are used to typeset printed matter....
- Monotype Corporation
Monotype Imaging Holdings is a Delaware corporation based in Woburn, Massachusetts and specializing in typesetting and typeface design as well as text and imaging solutions for use with consumer electronics devices. Monotype Imaging Holdings is the owner of Monotype Imaging Inc., Linotype,...
- Lanston Monotype
External links