1851

A model (of what?)

Some sort of pump...?

The pump idea isn't bad. I wonder if it isn't a science lab demonstration apparatus, perhaps comparing two types of pumps or maybe demonstrating the operation of a two cylinder engine of some sort.

Miniature steam engines (complete with fake bricks) are definitely a thing; but I'm wondering whether this is a static museum display rather than a working model.

Perhaps a compound reciprocating steam engine (HP cylinder on L, LP cylinder on R?)

The Crystal Palace building was 1,851 feet (564 m) long, with an interior height of 108 feet (33 m). It had an exhibition space of over 990,000 square feet (92,000 m2). It contained over 13,000 exhibits from places such as Britain, New Zealand, Denmark, India, Switzerland and France.

"The view of the west side of Front street, looking south from Pine, in 1852, is of particular interest because it shows some of the well-known pioneer citizens of Portland, besides giving a very good idea of the business district in those days. The men in the picture, reading from left to right, are: C.P. Bacon, Adolph Miller, Thomas J. Dryer (editor of The Oregonian at that time), W.H. Barnhart (in the doorway), H.W. Corbett, John M. Breck and W.S. Ogden. The dray was the first in Portland and, therefore, an object of considerable interest in those days. It was purchased in San Francisco by Mr. Barnhart for $400 and sold to Mr. Miller. The first building in the foreground is the general store of Breck & Ogden. Just beyond it is the general store of W.H. Barnhart & Co., part of which was occupied by the first Wells-Fargo Express office. The large building beyond was the store of H.W. Corbett. A vessel may be seen in the harbor at the end of the street." "Historic Pictures Mark Progress of Pioneer Portland," Morning Oregonian, Feb. 4, 1911, p. 6