[78-L] Long Play records

[DAVID BURNHAM]

I was just going through a pile of records I got from Philadelphia and I found the "RCA Victor Demonstration Album", a 10 inch 33 1/3 record.  This record was designed to demonstrate the Long Playing transcription records from the early '30s and the sleeve notes contain instructions about how to play them.  It says only to use the "orange shank long playing needle".  It also says not to use this needle with standard 78 rpm records.  Elsewhere it says, "Twenty minutes of delightful entertainment have been recorded in its super-fine grooves...".  This implies that the needle and groove are of different dimensions than standard 78 grooves.  I have always believed that these transcriptions had the same size groove as normal 78s.  Am I wrong?  Does anyone know about this??

Another record I found in the same pile is an Audiophile microgroove 78 rpm record, with the instruction, "Play with one-mil stylus only.".  I've never seen one of these before, but they must be a product of the '50s since there would have been no one-mil styli any earlier.

Thanks!