Technology System of Electricity Tab 3  Alexander Hogg  c.1788

Read's Electrical Machine, Nairne's Electrical machine, Torricellian Vacuum, Henly's small Phials...

Antique Copper engraving engraved by Rennolds, printed on hand made hemp and flax laid paper.

Published "According to an Act of Parliament" by Alexander Hogg, at the Kings Arms No 16 Paternoster Row, London circa 1788

Condition= Excellent with no discolouring, foxing. Soft fold in top right corner.

Nikola Tesla played his role with electrical inventions and patents at the turn of the 20th century but much had already been done as shown here: Edward Nairne (1726-1806) Nairne patented several electrical machines, including an electrostatic generator consisting of a glass cylinder mounted on glass insulators; the device can supply either positive or negative electricity, and was intended for medicinal use. In the eighth edition of the instruction manual for this device he claimed that "electricity is almost a specific in some disorders, and deserves to be held in the highest estimation for its efficacy in many others". He recommended its use for nervous disorders, bruises, burns, scales, bloodshot eyes, toothache, sciatica, epilepsy, hysteria, agues etc. William Thomas Henly (Henley) improved an apparatus for regulating and transmitting electric currents. Evangelista Torricelli produced the first laboratory vacuum in 1643, and other experimental techniques were developed as a result of his theories of atmospheric Pressure. A torricellian vacuum is created by filling with mercury a tall glass container closed at one end and then inverting the container into a bowl to contain the mercury.

Plate mark = 23.5 x 38 cm / 9.4 x 15.2 inch