Nightcrawler - - -
I assume you mean the 1878 DA model. Yes, this was a solid frame gun, much like the Single Action Army. It had a fixed cylinder and loaded and ejected like the SAA. The loading gate, if I recall correctly, had a sort of button extension on it to assist in opening the gate.
I don't have references at hand, but I believe the 1878 was offered in .45 Colt, .44-40, .38-40, and one or two British cartridges. Besides the books referenced by
Lone Star, there's a lot of information and illustrations in Wilson & Southerland,
The Book of Colt Firearms, recently reprinted.
And, as
LS mentioned, Colt's made some of the Model 1878 with enlarged trigger guards for use with big gloves on--I think this was marketed as their "Alaskan Model," and was pretty popular in the northern gold rushes. As an aside, this was a pretty large framed-revolver, and I've seen photos of smaller people using two fingers on the trigger. A similar model/option was offered, I think, on the New Service Colt. I think this was called the Philippine Model, and the smaller-statured members of the Philippine Constabulary often did the double-trigger-finger thing.
Lone Star also references the 1909 model Colt DA, which was another New Service variant. A bit of trivia of which I was unaware until recently: There was actually a special 1909 cartridge brought out for the latter revolver. It was simply a standard .45 Colt round with a slightly larger rim. I don't have the dimensions at hand. This was because the original .45C rim was pretty scanty and the extractor on the swing-out DA cylinder didn't always hold the rims properly for ecection. The ammo would fire fine, though. At a glance, the ammo appeared identical, but the 1909 cartridges wouldn't allow an SAA to function as a six-shooter--The chambers were too close together for adjacent chambers to be loaded with the 1909 ammo--So one either had to modify the rims, or be content with loading not more than three rounds in the SAA cylinder.
One more near-useless bit of firearms information, brought to you, courtesy of The Firing Line.