A total solar eclipse occurred at the Moon's descending node of orbit on Friday, August 21, 1914,[1] with a magnitude of 1.0328. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. 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. Occurring about 2.7 days before perigee (on August 24, 1914, at 6:30 UTC), the Moon's apparent diameter was larger.[2]
The totality of this eclipse was visible from northern Canada, Greenland, Norway, Sweden, Russian Empire (the parts now belonging to Åland, Finland, Estonia, Latvia, Lithuania, Belarus, Ukraine and Russia, including cities of Riga, Minsk, Kiev and northeastern part of Vilnius), Ottoman Empire (the parts now belonging to Turkey, northeastern tip of Syria and northern Iraq), Persia and British Raj (the parts now belonging to Pakistan and western tip of India). A partial eclipse was visible for parts of northeast North America, Europe, North Africa, East Africa, and the Middle East. It was the first of four total solar eclipses that would be seen from Sweden during the next 40 years. This total solar eclipse occurred in the same calendar date as 2017, but at the opposite node.
Several astronomers were setting up to observe the eclipse, in part as an attempt to confirm Albert Einstein's theory of general relativity. However, due to the onset of World War I as well as cloud cover, these experiments were unsuccessful.
A number of observatories sent expeditions to Russia to observe the eclipse including those from Argentina, the United Kingdom, Germany, Russia, and the United States. The expeditions led by Charles Dillon Perrine of the Argentine National Observatory, Erwin Finlay-Freundlich of the Berlin-Babelsberg Observatory, Germany, and William W. Campbell of the Lick Observatory, California, included in their programs the second attempt to verify the general relativity theory of Albert Einstein. (Perrine had made the first attempt at the 1912 solar eclipse in Brazil.[3]) However, World War I broke out and Freundlich and his equipment were interned in Russia, unable to carry out the necessary measurements. C. D. Perrine and W. W. Campbell, from neutral countries, Argentina and the United States, were permitted to continue with their plans, but clouds obscured the eclipse.[4] Perrine was able to obtain one photograph of the eclipse but the thin cloud cover was enough to obscure star locations necessary to test Einstein's theory.[5]
Shown below are two tables displaying details about this particular solar eclipse. The first table outlines times at which the moon's penumbra or umbra attains the specific parameter, and the second table describes various other parameters pertaining to this eclipse.[6]
| First Penumbral External Contact | 1914 August 21 at 10:12:09.6 UTC | |
| First Umbral External Contact | 1914 August 21 at 11:25:24.7 UTC | |
| First Central Line | 1914 August 21 at 11:26:20.7 UTC | |
| First Umbral Internal Contact | 1914 August 21 at 11:27:17.1 UTC | |
| Equatorial Conjunction | 1914 August 21 at 11:55:06.4 UTC | |
| Ecliptic Conjunction | 1914 August 21 at 12:26:24.1 UTC | |
| Greatest Eclipse | 1914 August 21 at 12:34:27.1 UTC | |
| Greatest Duration | 1914 August 21 at 12:34:52.8 UTC | |
| Last Umbral Internal Contact | 1914 August 21 at 13:41:59.4 UTC | |
| Last Central Line | 1914 August 21 at 13:42:58.0 UTC | |
| Last Umbral External Contact | 1914 August 21 at 13:43:56.1 UTC | |
| Last Penumbral External Contact | 1914 August 21 at 14:56:55.9 UTC |
| Eclipse Magnitude | 1.03276 | |
| Eclipse Obscuration | 1.06658 | |
| Gamma | 0.76546 | |
| Sun Right Ascension | 09h59m08.5s | |
| Sun Declination | +12°18'56.8" | |
| Sun Semi-Diameter | 15'48.7" | |
| Sun Equatorial Horizontal Parallax | 08.7" | |
| Moon Right Ascension | 10h00m29.2s | |
| Moon Declination | +12°59'43.6" | |
| Moon Semi-Diameter | 16'09.7" | |
| Moon Equatorial Horizontal Parallax | 0°59'18.8" | |
| ΔT | 16.7 s |
See also: Eclipse cycle. This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two (or occasionally three) eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months (173 days) later; thus two full eclipse seasons always occur each year. Either two or three eclipses happen each eclipse season. In the sequence below, each eclipse is separated by a fortnight.