Note 73 — PART SECOND. NOTES ON THE ILLUMINATION OF LIGHTHOUSES, WITH SHORT NOTICES OF THEIR EARLY HISTORY. (continued 3)
Reading edition
An apparatus of 0m.·185cm. was recently added to the list of French lights under the name of the Fifth order; while that of 25cm. radius has been called the Fourth, and that of 15cm. radius is styled the Sixth order. Those minute subdivisions I consider to be unnecessary.