Projection lab

August epicycloidal projection: interactive map

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Map toolsCountries, projection, and layers

Select map projection:

Add a country or US state:

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Quick start

Add a country or US state, then drag its outline anywhere on the map.

Map center

Country at the center

Find a country

This view keeps its special layout. Your selected country is remembered. Choose Equal Earth to place it at the center of a flat map.

Change the world's centerOpen the full map with a country at its center.

About this map

Move countries and US states across the map, switch on distortion layers, and see what the August Epicycloidal projection changes.

✈Great circle vs rhumb line: routes tool↗Projection Details ↗Conformal, epicycloidal. The whole world fits inside the kidney-shaped outline of a nephroid, a two-cusped epicycloid.

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Atlas of error · liveAugust EpicycloidalClick or tap a country to add its outline

Click a country on the map to add its outline.Tap a country on the map to add its outline.

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August epicycloidal projection at a glance

Distortion class: Conformal
Graticule type: Epicycloidal
Creator: F. August and G. Bellermann
Year: 1874
Area: Highly distorted: scale increases rapidly away from the center, with the greatest enlargement toward the 180th meridian
Shape: Preserved locally (conformal, with no singular points)
Distances: Highly distorted
Angles and directions: Preserved locally (conformal)

Add countries from the tools panel and drag them to other latitudes. The outline keeps its true shape and area on the globe, so any change in its size on the map shows this projection's distortion. Tissot's indicatrices and the area distortion map show the same effect across the whole world.

Full guide: August epicycloidal projection →Compare with another projection →Quiz: name the projection →