----------------------------Original message---------------------------- Reply by : Gregory F. Durocher@Alaska@RMMC Date : Friday, May 3, 1996 15:31:14 Reply to : iSMTP@RMMC1@Servers[<[log in to unmask]>] Reply: You are correct: the numbered circles on the provisional series maps are the centers for the aerial photography used in producing the map. The number to the left of the hyphen is the roll, and the number to the right is the frame. Greg Durocher USGS - Earth Science Info. Ctr. -------------------------- [Original Message] ------------------------- To : "Multiple recipients of list MAPS-L" <[log in to unmask]> From : Ken Rockwell <[log in to unmask]> Subject : Obscure symbol on provisional topos Date : Friday, May 3, 1996 at 1:22:32 pm MDT ------------------------------------------------------------------------------ ----------------------------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!"