No, I just found the numbers here in an envelope 
Sorry for the mistake – we have had a few errors over the last few issues as I get used to a different workflow with a new designer.
The gearcutter pictures are 27, 28 and 29 if anyone wants to write them in; not sure it was that hard to figure out which is which without the numbers.
Arduino starts with photo 9 and they follow in sequence.
In general terms, I try to number all photos and caption them where it makes sense to, but if an article is illustrated by several angles of the same item I won't put captions like 'yet another picture of it but from the left hand side this time'.
Many authors don't include captions, and if possible I get back to them and ask for a list, but if I don't get this in time I may have to make them up myself. Naturally author's own captions are better as they can highlight key points.
Sometimes I get articles without photo references; it can be a struggle to ensure they go in the right places.
Sometimes I get captions and references but the numbers don't match the photos – this is a bit like solving a jigsaw…
A few authors don't supply either captions or photo references – at this point I start losing hair…
Sometimes I get a very large number of photos without captions or references and a note 'I've sent you plenty of photos so you can choose the best ones to illustrate the article' – at this point I lose the will to live 
Neil