Painted glass Christmas and New Year decorations are pictured at the “Yolochka” (Christmas tree) factory, which has been producing glass decorations and toys for the festive season since 1848, in the town of Klin outside Moscow, Russia, November 24, 2016. (Photo by Maxim Zmeyev/Reuters)

A tourist poses on the glass-bottom bridge at Zhangjiajie Grand Canyon on August 20, 2016 in Zhangjiajie, Hunan Province of China. The Zhangjiajie Grand Canyon's glass-bottomed bridge welcame its trial operation on Saturday and about 8,000 tourists crowded to view the grand glass bridge. (Photo by VCG/VCG via Getty Images)

A publican serves a glass of stout to a donkey in the East End of London, 1960s. (Photo by Steve Lewis/Getty Images)

A hungry tiger was almost left with a ROARing headache – after nearly colliding into a pane of glass as it dived underwater for a slab of meat. (Photo by Caters News)