----------------------------Original message---------------------------- Hi Ken- Yes, those are references to the aerial shots used to make the provisionals. I like them because we have a fairly good set of the GS aerials, and I can use them like line indexes. Be aware that sometimes they are refering to HAP shots. Hope this helps. Sue Trevitt-Clark University of Oregon On Fri, 3 May 1996, Ken Rockwell wrote: > ----------------------------Original message---------------------------- > A patron asked me the meaning of a symbol on a provisional edition > of a topo sheet, and I didn't recognize it. It looks like > "crosshairs," i.e., a circle divided in four, and it occurs in > various places on the map. Next to each one is a hyphenated group of > numerals, such as 1-112, 2-27, etc. My guess is that it has to do > with the sequence of aerial photos used for surveying the area, and > that they'll gone if the sheet is published in its final form. Is > this correct? -- KR > > > > Ken Rockwell > "Just another map librarian" at > Marriott Library > University of Utah > Salt Lake City, Utah > > "Without Geography--you're NOWHERE!" >