For people like newspaper reporters, sales reps and professionals delivering a lecture or paper, the furthest extent of metro NYC is pretty easy to measure.
If you can get into work early, check in and then take a car or train to the location, do some useful business and then return late to the office, and then still later home to sleep in one's own bed, it's still metro.
Rising early and home late may be hellish and the checkins at the office bookending your work day may be mere tokens but it avoids that expensive hotel room and best of two days (or more) away from family and office.
The time of day for your key business is paramount - an evening lecture or presentation makes the circle of distances evoke by words 'metro NYC 'very much much smaller.
Measuring the extent of metro NYC is important in the tale of the Gotham Eight because metro residents shared a lot in common with Dr Dawson and his team.
Metro residents all heard NYC radio, possibly watched - even then - NYC TV , read the big NYC papers , understood all the local NYC area references , took in big NYC movies and musicals and sports events.
You were among your own kind, sharing a common metro culture - even in fairly frequent (because it was relatively inexpensive) all important 'personal' contact.
By contrast, Dawson's infrequent but extended wartime trips ( all prior to his late 1942 success with SBE) to such places as Baltimore, Washington DC, St Louis , Louisville, California , even his native Nova Scotia took him into fairly alien terrain.
In wartime conditions of restricted travel and censorship, and given his rapidly declining health, Dawson's post November 1942 success with penicillin for SBE was not known beyond metro NYC's medical and research community.
But a community he had been very active in , for almost twenty years.
And fortunately for all of us , the small wartime fish bowl he was stuck in (metro NYC) was a community with more people than most 1940 nations, living in close proximity with good intersecting communications and was home to much of the regional, national and global media.
So while it is true that word of his SBE successes spread only locally inside the fish bowl via local medical gossip (noting that in wartime gossip becomes much more important and much more believed) , only London could really equal metro NYC as a fortunate and powerful fish bowl to be stuck in....