Marauder's map, Quirrell and related issues

[Geoff]

No: HPFGUIDX 191971

Geoff:
I want to try to pull together some of the ideas linked to the above. There 
have been a number of different threads and sometimes, group members 
have written a number of replies with information which might have more 
usefully been in one post... which makes life a bit confusing.

However. Reading Bart's post about the map reminded me of what happens, 
certainly with some modern mapping tools. I frequently use Google Maps and, 
after you enter a UK postcode, you get a small scale map with your target in 
the middle as a miniscule bit of the whole. Sometimes the place you want -
say a road, isn't visible until you home in on the place you seek and gradually,
the detail improves. 

Canon does give us some idea of its dimensions:
'Fred pulled something from inside his cloak with a flourish and laid it on one 
of the desks. It was  a large, square, very worn piece of parchment with nothing 
written on it.'
(POA "The Marauder's Map" p. 142 UK edition)

'Large' is obviously relative if it fits under a cloak but it does lend agreement 
with the suggested size given in a recent post.

The other two things cover Voldemort and Scabbers. I have already suggested 
that perhaps the Map recognised people by their magic signature and that, when 
Voldemort was possessing Quirrell, the latter's signs were the ones which 
defined the person the Map was trying to identify.

In the case of Peter Pettigrew, the thought which more recently occurred to me 
was since he remained permanently in his Animagus form, perhaps the Map 
didn't pick him up, being only designed to find people.

On this same topic of the twins not noticing names, assuming that my last 
hypothesis was incorrect, I cast my mind back to my Grammar school in South 
London. There were about 80 guys in my year and three classes. Now, I knew 
all the boys in my form but my knowledge of those in the other forms was 
sketchy because, in the lower school, we didn't meet up often in groups.

When I got to the dizzy heights of the Second Year and higher, we took little 
notice of students in lower forms; they were largely below our radar. Unless 
they were looking for guinea pigs to test their jokes, I think they would be 
working on other things - japes and tricks to play on their own peers or 
sneaking off somewhere. I really doubt that they would be watching Ron 
on an organised basis; their interactions with him and  folk like Harry seem 
to have usually been extempore as and when they met.