A total solar eclipse occurred at the Moon's ascending node of orbit on Monday, July 28, 1851, with a magnitude of 1.0577.

A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness.

Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide.

[1] The path of totality was visible from parts of modern-day Canada, Greenland, Iceland, Norway, Sweden, Denmark, Poland, Russia, southwestern Lithuania, Belarus, Ukraine, Moldova, Georgia, Armenia, and Azerbaijan.

This was the earliest scientifically useful photograph of a total solar eclipse, made by Julius Berkowski at the Royal Observatory in Königsberg, Prussia.

Partial eclipses, in which only a portion of the Sun's surface is obscured, are relatively common due to the width of the Moon's outer shadow, or penumbra, which may be several hundred miles wide.

Total eclipses occur when the Moon's inner shadow, or umbra, reaches the surface of the Earth, completely obscuring the Sun over a much narrower portion of the ground.

The Sun's outer atmosphere, or corona, is normally invisible due to the brightness of the solar disc, but becomes visible from Earth during a total eclipse.

For this occasion, the Royal Prussian Observatory at Königsberg (now Kaliningrad, Russia) commissioned one of the city's most skilled daguerreotypists, Johann Julius Friedrich Berkowski, to record a still image of the event.

[2] The observers attached a small six-centimeter refracting telescope to a 15.8 centimeter Fraunhofer heliometer, and Berkowski made an eighty-four second exposure shortly after the beginning of totality.