Photo: Printing press driven by the heat rays of the sun.
On 6 August 1882, Monsieur Abel Pifre, a French Engineer, demonstrated the solar engine invented by him at a meeting of the Union Francaise de la Jeunesse held at the Jardin des Tuileries in Paris.
It consisted of a concave mirror 3.5 metres in diameter, in the focus of which there is placed a cylindrical steam boiler equipped with a safety valve.
The steam generated by the reflected sun-rays actuates a small vertical engine of 2/5 horse power driving a Marioni type printing-press.
Although the sun lacked power and the sky was frequently overcast, the press operated continuously from 1.00 pm to 5.30 pm turning out an average of five hundred copies per hour of a journal which was especially made up for the occasion and appropriately called Soleil-Journal.
Previously Pifre had demonstrated that 50 litres of water could be brought to boil in less than 50 minutes, after which the pressure of the steam increased 1 atmosphere every eight minutes.
There is little doubt that such a solar engine will be a boon to the population of hot areas which so often suffer from a shortage of fuel.