Updated by Steve Bartley, naming this as the source of information: The Sunday herald & weekly national intelligencer, June 21, 1891, Page 9;Evening star., June 16, 1891, Page 8;The evening times., May 23, 1902, Page 6.
The DC newspapers for 1891 give only a little information concerning the physical size of the organ, and compare it to other large organs.
The Glen Echo Chautauqua Institution was a summer park patterned after the larger Methodist camps popular in the 19th century. Built by two wealthey brothers, they had a trolley line run from Washington DC to this rural area on the Potomac river, in Montgomery County MD. Many stone buildings were erected, in the Adirondack style. The park did not pay for itself and the organ was finally put up for sale in 1902, being bought by Samuel Sunset Waters, a DC organist-organ builder.
As the rest of the park was also put up for sale, the organ seems to have stayed in situ for a while, as it was advertised with the rest of the park in subsequent newspaper ads. Being a new organ, it seems likely to have been reinstalled in a new location, but research has yet to reveal where.
Contracted by National Assembly at Washington D. C. To be opened June 16 1891. Pneumatic compensating valves for Great and Swell. Ross Water Motor. The Institution built a new amphitheatre in 1893. Did this instrument go there?