Who was Captain Craig? It seems he was directed by a (presumably superior) officer to tell the folk of 1898 about the extreme convenience and portability of a particular make of field glasses. We suppose he must have been more well known to us than the USA's Chief Signal Officer at the time. Otherwise why would said CSO not volunteer the recommendation himself under his own name?
One might imagine at the time, upon being told that these field glasses were recommended by the authority of the Chief Signal Officer of the United States Army, no less, that we would have remained unimpressed. 'Who is he?' we would have said, with a certain disdain. (It was 1898 so of course we would assume it to be a he). But Captain Craig - well, if he likes them then they must be good. We trust him.
On the other hand he was ordered to do it. Hmm.
Mr Aitchison might be pleased to see his device fetching one hundred and twenty quid at an auction - but, taking inflation into account, five guineas back then is suppsedly equivalent to about three hundred pounds today. But I suppose they would be second-hand.
Here are a few more ads of the time, as a bit of context.
We like the first one. Very steampunk.