The question of ch must be treated in close connexion with that of another digraph, namely sh, with which everybody all over the world is familiar from such names as Shakespeare, Sheffield, and from words like shrapnel. This sh is found in Ido in a certain number of words, which seem worth of admission into our language on the principle of being known to a greater number of people than other expressions for the same ideas; some of them are common to E D Sc, others are found only in one or two of these languages; I give the most important of them, and quote them as above without any grammatical endings: sham, shark, shel, shild, shirm, shov, shovel, shu, shultr, shutr.
The problem now arises: are we to keep both these digraphs, or can we simplify matters by having only one of them? The latter procedure seems preferable, as no ambiguity seems likely to arise by fusing them into one, and as probably no new words will call for admission which require the distinction. But then the question is to choose between the two spellings, and what pronunciation to give to the uniform digraph--a most intricate question. Ch is pronounced [S] in F, [tS] in S and generally in E, though there are some E words in which ch has the F simple sound: among them champagne, charade, charlatan, chauvinist, chicane, machine. Machine is written maschine in D, thus with the same sound. Cheque (American spelling check) in the meaning 'order to banker' in D has become scheck. This would seem to speak in favour of adopting everywhere the sound [S] without initial [t], the more so as a pronunciation [tS] would be extremely unnatural in such words as E shame, shoe. But then, are we to spell shanj-, shambr-, etc.? Or to introduce the F spelling ch everywhere and write cham-, chu- for shame, shoe, etc.? Neither way out of the difficulty seems satisfactory in every respect, and I am afraid I have in this particular point nothing better to offer than to keep provisionally both spellings and to allow everybody full liberty to pronounce [S] or [tS] just as he likes. It is perhaps fortunate that there are some points in which we can allow each individuality a full scope without any danger for mutual understanding.
Some time in the future it may be possible instead of the digraphs sh and ch to use the phonetic symbol [S].