"Student" lamp

Student' lamp, about 1830, which could be adjusted in height to suit the user and included a green shade to reduce glare. Fuelled by colza (rapeseed) oil, the lamp's reservoir was higher than the wick, and the oil, which was viscous like modern cooking oil, flowed down under gravity. A series of metal float valves faced with cork controlled the amount of air and oil flowing in and out of the reservoir.