Why was Brachygraphy difficult to learn?

A page in a book. The paper shows age staining. On the page is printed a table. Above the table is the number three in brackets. The table is headed 'Arbitrary Characters for Prepositions and Terminations &c.' The table lists Brachygraphy characters in three narrow columns, each next to a wider column listing the accompanying definitions.

'there then appeared a procession of new horrors called arbitrary characters...' (David Copperfield, chapter 38)

A page from Gurney's Brachygraphy manual.

Dickens’s ‘very difficult art’ became a ‘savage stenographic mystery’ in David Copperfield.[1] Dickens found Brachygraphy hard for a number of reasons. The system was based on transcribing words using symbols of circles, lines and hooks to stand for consonant letters while omitting vowels.

As we know from our own text messages, this works well for an easily recognisable sequence like /tmrw/ because the shorthand can only be read one way. However, it is less effective for a short sequence like/fl/ which can be read in multiple ways (fall, foul, fell, fill, fail, foal). It was a system that was easier to write than it was to read and not at all user-friendly.

Alongside the consonant letter symbols, Dickens also had to memorise 74 ‘arbitrary characters’, which stood for random individual words or parts of words. Many of them, such as the symbols for ‘magnify’ and ‘foundation’ or ‘from one end of the world to the other’, were pointless to learn because they occur so infrequently in speech. No wonder David described the arbitrary characters as ‘wretches’ and ‘despotic’.[2]

References

[1] ‘To Miss Burdett Coutts, 14 January 1854’, in The British Academy/The Pilgrim Edition of the Letters of Charles Dickens: Volume Seven, 1853-1855, edited by Madeline House, Graham Storey, and Kathleen Tillotson (Oxford: Clarendon Press, 1993), 245; Charles Dickens, David Copperfield, edited by Jeremy Tambling (London: Penguin, 2004), 632.

[2] Dickens, David Copperfield, 551.

Section One: Learning Shorthand
Why was Brachygraphy difficult to learn?