Jet activity in the central BH of the Milky Way in 4th and 14th centuries CE

This paper discusses the historical evidence for the jets from the central Black Hole of the Galaxy in the 4th and 14th centuries. We suggest that the apparitions of a "lightening cross" during the day time recorded in 312, 351 and 1317 were caused by the line of two jets beamed back-to-back from the central black hole and crossed the visible projection of the Galaxy disc. All three historical accounts that record the flashing signs of a cross give precise time and geographical locations of these astronomical events (the vicinity of Rome, Jerusalem and the vicinity of Moscow respectively) and most importantly the position in the sky in connection to the Sun. These positions coincide with the location of the Milky Way center on the sky in these specific places and dates. Therefore, it is logical to assume that the intersection of the jets and the lighted projection of the Galaxy disc was the source of the cross visions in the Middle Ages. The forth evidence of crossing lights is found in russian chronicle under 1377 year. This event took place in the night sky under Moscow.