Why Linotype Succeeded

For several years I wondered why Linotype succeeded after so many earlier attempts to mechanize typesetting were only marginally successful, or unsuccessful. In January 2018 I decided to consult Ellic Howe's The London Compositor: Documents relating to Wages, Working Conditions and Customs of the London Printing Trade 1785-1900 (1947) wherein I found a detailed technical and economic answer to this question on p. 62, which I quote:

"(IX) The Introduction of Composing Machinery

"The difference between the type-setting machines and the Linotype matrix composing and slug casting apparatus, first used in this country in 1889, must be explained. The type-setting machine consisted of magazines loaded with normal printing types. The operation of a keyboard released the types from their containers, whence they fell by gravity and were moved to the 'stick'. At this point they were justified by hand, either by the keyboard operator or by an an assistant sitting beside him. The galleys would be corrected by hand, and the pages made-up, imposed and printed off in the usual manner. Distribution was effected by hand or a separate machine. Where the latter was employed, specially nicked types were required. These typesetting machines were capable of at least 6,000 ens per hour, when operated by a moderately skilled man. This was three times the output of a really fast hand-compositor. It was found, however, that although the use of the machines both increased and speeded up production, their employment was uneconomic unless the distribution could wholly be attended to by cheap labour, either youths or females. Such a course was never tolerated by the London Society of Compositors, and type-setting machines were rarely used in London. Outside London, where trade union restrictions were not so firmly enforced, a different state of affairs prevailed, and a number of provincial newspapers used the machines between 1870-1900.

"The introduction of the Linotype, first used for a New York daily sheet in 1886, produced far-reaching results. Movable types stored in magazines were replaced by matrices. Manipulation of the keyboard released the matrices, which were directed to a point at which they were justified to the correct measure by wedge-shaped spaces. The line of matrices was then mechanically transferred to a position in front of a mould, into which molten type metal was automatically pumped. A line-o'-type, or solid slug, was then ejected, completely ready for make-up, unless corrections were required, which were made by resetting the line completely. The matrices were then automatically lifted from the mould and returned to their respective magazines. Used type matter was melted down. The time was later to come when the equipment of a composing room could be judged, not by the amount and variety of types held in cases, but by the variety and excellence of design of the matrice repertory. The success of the invention, both in the provinces and in London, was immediate. The problem of distribution disappeared, and the slugs were easier to handle in a busy newspaper composing room than loose type. The endless expense of replenishing the type cases was also at an end, since a freshly cast printing surface was used for every issue, thus affording better quality stereotype plates."