Published in Imagi 5, 2 (1950), 2, Moore’s poem contrasting economy and excess features a process by which an engineer used Plexiglas to model a way to cut steel economically from flat sheets into triangles to be fitted together as a sphere. She cites an article from the New York Times which indicates that a steel globe was made in this way for the Navy. Buckminster Fuller’s Dymaxion Map displays the principle whereby twenty triangles make a sphere:
Dymaxion Map Unfolded
Dymaxion Map Sphere
What Moore perhaps did not know was that Mr. J. O. Jackson, the inventor, worked for Pittsburgh-Des Moines Steel; that may not have mattered much to her, but in 1967, she may have noted that this was the company that constructed the “Gateway Arch” at St. Louis, her first home stomping-ground (and would surely have inspired another “Granite and Steel” had it been completed earlier).
Moore credits the first four lines of “The Icosasphere” to Edward McKnight Kauffer, an American graphic artist (1890-1954) whom she met after he returned to the States from London where he had a successful career as an advertising poster artist, principally for the London Underground.
Edward McKnight Kauffer
Kauffer and Moore became close friends. His wife, Marion Dorn, an interior designer, referred to herself and Moore as “The Dromios,” given the similar pronunciation of their first names. For a first-hand treatment of Moore’s relationship to the Kauffers, see Grace Schulman’s article “Marianne Moore and E. McKnight Kauffer: Two Characteristic Americans,”
Twentieth Century Literature (30:2-3), 1984 Summer-Fall, 175-80. Kauffer and his work were brought to the attention of American Airlines through Bernard Waldman, Schulman’s father, and he became a family friend.
Today, Kauffer’s posters have become classics. Exhibitions abound, the internet has many images of his work, and one poster from 1918 recently sold at Christie’s for more than $40,000.
Kauffer never created a poster for “Buckinghamsire hedgerows” but there is one that may give some sense of his art at a not too distant remove.
"North Downs" by Kauffer,
“The North Downs,” 1916, advertised transportation to the chalky hills that run for many miles through Surrey and Kent down to the Dover cliffs. While in the opposite direction from London as Buckinghamshire, which lies to the northwest on the way to Oxford, the hedgerows in the image must bear some resemblance to those further north. In any case, Kauffer’s description of birds building nests in “parabolic concentric curves” is an excuse to enjoy, here, one of his posters.
Two online biographies give further details about Kauffer: AIGA official cite is http://www.aiga.org/content.cfm/medalist-emcknightkauffer
The British Design Council has a slightly different version at http://designmuseum.org/design/page74546.
Kauffer’s design for the jacket of Ulysses (Random House, 1946) may be the most familiar image for Americans: 
Marianne Moore: Poetry 