RE: Bunnypuncher's daily giveaway 7/26/2018 - 15 SBD total in prizes

[vanj]

#5: Optical Lenses (13th Century) Reflecting light through glass.
#4: Semiconductor Electronics (Mid-20th Century)
#3: Penicillin (1928)
#2: Electricity (Late 19th Century)
#1: The Printing Press (1430s)