"Gentleman" at center appears to be 3d woman of group. Looks like Margaret Hamilton (Wizard of Oz).

On closer examination, it's obvious that Nemo is in fact a steam launch. There's firewood piled just forward of the boiler. Steam launches burned wood or coal; naphtha launches burned...naphtha.

What do you make of the military style tunic on the gentleman in the center of the party? Is that recognizable as part of the circa 1897 uniform of any service? What say ye, Shorpy Sleuths?

A comment by SouthBend states that naphtha can not cause a Boiling Liquid Expansion Vapor Explosion, but steam can. This is exactly backwards. Steam does not explode. It can cause a rupture of a boiler, but it will not explode. Naphtha, and more usually, light natural gas liquids such as propane are prone to BLEVEs. A BLEVE is caused when a fire impinges on a pressure storage vessel, suchas a railcar, and weakens the wall of the vessel. The liquid inside is hot because of the fire, and when the vessel fails, the liquid hydrocarbon boils out and escapes as an expanding vapor cloud, and that cloud will explode when it finds an ignition source, e.g., the fire that caused the rupture in the first place. BLEVEs are extremely powerful, and scary as hell.

"I can tell you that these folks will soon have about a thousand red ants as guests for that lunch"

The red fire ants common to Florida and the SE USA started showing up in the 1930s and spread rapidly thereafter. In the 19th century they weren't present. There were native fire ants but their behavior is much different, they don't sting, and weren't much of a problem.

William Henry Jackson took several views of this picnic party. The LOC has other images from the same event scattered in their negative records but brought together by the keyword "Tomoka." Other images in this set reveal that the launch in the picnic photo was named the Nemo.

[Seen earlier here and here. - Dave]

I'm thinking there has to be one nearby!

In the luncheon party there is one more guy than girl.
Maybe she's the shutterbug.

[William Henry Jackson was the photographer here. One the enormous view cameras used to expose these 8x10 inch negatives can be seen folded up on top of the boat next to a carrying case for the glass plates. - Dave]

That fantail-stern launch is certainly a handsome little vessel!

It's either s steam launch or a naphtha ("vapor") launch. Some launches used naphtha as the "working fluid" rather than water.

The reason for this was that some states required (and still require) a steam boiler operator license above a certain steam pressure.

A naphtha boiler, although it sounds dangerous due to flammability, cannot cause the type of deadly Boiling Liquid Expanding Vapor Explosion (BLEVE) which a steam boiler can.

I think this one is a steam launch, because it has a whistle. I can't see how a naphtha launch could have a whistle; dangerous vapor would issue forth.

Of "Luncheon of the Boating Party" or, at best, the economy class.

There's some gear over near the picnic. It looks like standard size stuff(8"x10"perhaps) for the time. But the really big camera is, I think, folded on top of the boat canopy, near the prow. 20" x 24" I'd guess. Not much enlarging in those days, so big picture=big camera. Is that the case for it back by the stern?

It's an American Seurat, Sunday Afternoon on the Island of La Grand Jatte.

Just around the bend from the famous Schweitzer Falls (named after Dr. Albert Falls). Keep your hands and arms inside --- dangerous hippos ahead! BANG!

We used to vacation at Ormond-By-The-Sea in the '50s, right across the river from Tomoka, and I can tell you that these folks will soon have about a thousand red ants as guests for that lunch.

This immediately reminded me of "The African Queen."