A FINE RARE AND EARLY CIRCA-1887 THOMSON-HOUSTON INCANDESCENT ELECTRIC LIGHTING DYNAMO in exceptional, original condition believed to be original paint and patina, not cleaned in any way, with a 4" x 3" heavy cast maker's plate with raised letters and stampings reading: "Thomson Incandescent Dynamo"; Volts - 110; Speed - 2,400; Class - D3S; No. 4184, adjusted for ___ per CT. loss, patented Sept. 2, '79, Oct. 5, '80, Oct. 10, '82, Jan. 5, '86, July 13, '86, Sept. 28, '86, patents applied for, manufactured by Thomson-Houston Electric Co., Lynn, MA. USA, with twin inverted 7" diameter x 7" high field coils in excellent tested order each with brass upper endplate, heavy cast armature frame with twin 3" diameter lifting eyes, twin top-mounted original slate terminal blocks with terminals and wired to brushes and twin output terminals, 6 1/4" diameter armature in what appears to be original brown paint corresponding to color of field coils, 3 1/2" diameter segmented commutator, heavy cast main bronze brush adjusting assembly with original hardwood handle and brass wing nut stop, twin heavy spring-loaded adjustable brush holders each with carbon brushes complete with knurled clamp, spring tension and adjustment screws, the armature supported on twin heavy cast base-mounted pillars each marked D3, each with adjustable main bearing, removable hinged brass access caps to main bearing oil reservoirs, each bearing stanchion with original brass sight glass, oil level gauge each with removable knurled cover, both with glass intact, belt-driven pulley 3 3/4" x 3 1/2" with crowned center section, 1" diameter armature shaft. Dimensions: length over shaft - 30" height to top of lifting rings - 22 1/2"; height to top of brush adjustment handle - 24"; height to top of terminal block - 21". Estimated weight approximately 600 lbs. +-. (See photo.)