In 1884 Elie Ferrand of Segonzac in the Charente, France, shipped two cases of his fine champagne cognac (1844) to Monsieur Gustave Trouvé, highly reputed electrical engineer at 14 rue Vivienne, Paris 2nd. In return, Trouvé him sent him one of his luminous electric walking sticks.
In November 2016, 124 years later, a descendant of the Ferrand family, searching in the attic of the family mansion discovered the cane covered in spider's webs and dirt. Unable to unscrew it, the cane was then taken to biographer Kevin Desmond's dentist, Dr. Pascal Ballarin of Carignan de Bordeaux placed it under the X-ray machine normally used to look inside his patients' teeth.
His composite image of 5 images shows that, extraordinarily, the tiny bulb, wires and even the battery (9mm x 7mm) are still in place. Recharging was done by inserting fine wires into pinholes.
Fine Example of this genius of electrical miniaturization!