This silhouette shows Fox Hunters on Horseback.
The Smithsonian has not yet included a high resolution download.
The Smithsonian has listed this image as CC0 so it is in the public domain.
Since it is CC0 you can right click the image (via the hyperlink above) and copy the screen image.
The resulting copy should do fine for online use.
(The image is only 72ppi so will have jagged edges if printed)
I experimented with Windows 10 "Snipping" tool.
(on keyboard press: Windows Key + Shift + S)
I cropped the picture by clicking and dragging the mouse.
A small auto pop-up stated "Snip saved to clipboard. Click here to markup and share the image".
Clicking took me to the "Snip and Sketch" (included in Windows 10).
I clicked the three ellipses on the top right, selected "print",
In the print pop-up I left the defaults alone and hit the "print" button at the bottom.
The resulting print wasn't great, but it wasn't too bad.
The image printed was 6 3/4" x 4 1/2"
I enlarged the image by photocopying and ended up with an image I can use to make a stencil.
Actually, I am more interested in making a stencil of just the trees :)
Source: Smithsonian Online Collection
©: listed as Public Domain with CC0 license
Cooper Hewitt, Smithsonian Design Museum
2 E 91st St, New York, NY 10128