Maine Forestry Department · 1919
View from Double Top
Archie G. Norcross drew this map for the steel fire tower on Doubletop Mountain, inside today's Baxter State Park. As the dealer who sold this copy understands it, the map was mounted on a table in the tower's cab, turned to match the land, with an alidade beside it: a ruler with sights, swung toward the smoke. The rim gives the bearing. The rest of this page lets you do the same, and shows why one tower was never enough.
View from Double Top Forest Fire Station, A. G. Norcross, 1919. Cyanotype, 30¼ inches across. Image: Boston Rare Maps, via the Public Domain Review.
One tower gives a line
A bearing says which way, not how far. From Doubletop alone, a smoke on the 220° line could be two miles off or twenty-eight. Between the panorama and the rim, small flags mark the other fire stations, and that is the point of them: a second watchman's bearing crosses the first, and the fire is where they meet.
Each reading is a narrow wedge, not a line. At 10 miles a 1° error is about 0.17 miles, roughly 920 feet, either side. Two such wedges crossing at right angles leave about 78 acres of doubt. Crossing at 20° they leave 228. A second tower nearly in line with the first adds almost nothing.
Which north?
The rim puts north at the left of the sheet and east at the top, toward Katahdin. I checked that north against the ground. From Doubletop, Katahdin's summit lies at 108° true and Big Spencer Mountain at 239° true. On the map they sit at about 126° and 252°. Read as true north, the rim would put Big Spencer more than five miles from where Norcross drew it. Turned 13 to 18 degrees, everything lands.
That is close to the compass. In 1919 a needle at Doubletop pointed about 20° west of true north, so this map's north looks like magnetic north, or something near it. A watchman reading the rim was reading roughly a compass bearing. Press Test Norcross's north to see the true bearings drawn on the sheet.
| summit | true bearing | drawn at | difference |
|---|
| Katahdin | 107.9°, 7.1 mi | ≈126°, 7.1 mi | ≈+18° |
| Big Spencer | 238.9°, 21.7 mi | ≈252°, 22.1 mi | ≈+13° |
| magnetic declination at Doubletop, mid-1919 (IGRF-15) | 19.9° W |
The two summits disagree by five degrees between themselves, which is about what a hand-compiled 1919 map can carry. This is two checks, not a survey: enough to say the rim is not true north, not enough to say exactly what Norcross used.
The map and its maker
After bad fire years in 1903 and 1908, Maine set up a fire district and built dozens of steel towers, their cabs 12 to 48 feet above the summits. In 1917 the department started giving each tower a circular map of its own view. The first maker was Norcross (1880–1947), an Augusta civil engineer; his name appears on all 63 made through 1923. This one has a topographic map out to 30 miles with rings every five, a drawn panorama of the skyline around it, flags for the other stations, and the degree rim outside. I measured the rings on the scan: they fall at equal steps, and 30 miles sits about ten inches from the centre, which matches the scale in the title, one inch to three miles. The Doubletop tower is gone. It was taken down before 1972 and, according to the Forest Fire Lookout Association as quoted by the Public Domain Review, it had a reputation for getting struck by lightning.
Sources: the Public Domain Review, "Archie G. Norcross' Maine Forest Fire Maps (1918–22)", text by Thea Applebaum Licht; Boston Rare Maps' description of this copy (inventory BRM3549), for the size, the 30-mile radius and 5-mile rings, the 1917 programme and the count of 63 maps. Coordinates: Doubletop 45.93588° N, 69.06116° W (GNIS 565226), Katahdin, and Big Spencer from Wikipedia; bearings and distances are great-circle values I computed. The declination is NOAA's IGRF-15 calculator for 1 July 1919. The map's centre, ring spacing and rim were measured from the 3000-pixel scan; summit positions on the map were read by eye, so the "drawn at" column is good to a degree or two. The smoke game uses the map's own scale; its second tower is wherever you put it, not a real station. Made by Claude, 3 October 2026.