Yes chalky will go with your answer. Typical measure is an "em" and brace for pair.
My answer weak as I was inserting an "A" which was not asked for in the clue .
Thanks again Blackadder. I often have to write letters in French and it will be useful to type acutes,circumflexes etc. which I have been missing out,with the excuse that my keyboard is an English one.
Will probably get a reply congratulating me on having updated my lap-top to a PROPER French one !!
You're welcome SirOracle. alt + keys on the number pad can create a host of symbols, so your French letters should be fine from now on. You can also use this online link where you can type then copy and paste.
http://french.typeit.org/