Hi Rick,

I would go with what you came up with measuring the bar scale on the map. You are partially correct about Google Maps and their use of a projection that might/could be different than the one used on the paper map and that alone could account for the discrepancy. In addition, screen resolution may also play a factor. All that said, as catalogers we are to describe from the resource, and so that is why I advise delivering what you got from the map itself. 

Paige
From: "Rick Grapes" <[log in to unmask]>
To: "[log in to unmask]" <[log in to unmask]>
Sent: Friday, May 18, 2018 2:55:26 PM
Subject: A scale question.

Hi all,

 

I have a calculating scale question.  This map I’m cataloging has a bar scale.  I measured the bar, did the math, and got the ratio. 

 

Just for the fun of it I also measured between 2 points on the map, as far apart as the map would allow, obviously much greater than the bar scale, then measured between the same 2 points on google maps, and again did the math.  The difference was about 10%.  Which calculation would you trust?  Granted, either entries in the 255 would be an approximation.  A potential issue could be divergent projections etc.  Any suggestions?

 

Rick Grapes

BYU Map Cataloger