Thorn pop pack 2 x 20w bedroom installation

Today's fluorescent installation is a twin Thorn switch start pop pock with a green and a blue 20w tungsram tube. This is in my bedroom in addition to the 5ft single pop pack. The new pop pack is operated separately by a pull cord switch. Both PPs have prismatic diffusers. The twin pp always takes me back to a primary school I attended for my last year that had a high quality installation of mostly 6ft srs pop packs with prismatic diffusers, probably a 1970s install.