On Monday, February 10th, at 9h 29m 30s, there was observed an instanteous bluish-white illumination in the atmosphere, so strong and vivid as to be visible in the inner rooms and in the open air.
The day was a magnificent one; blue sky, no wind and a raidiant sun. Soon after there was plainly visible near the zenith and some few degrees to the SE, a white spot, like smoke, bearing NE to SW of about 6 degrees in length and 1 degree in width; its form was semicircular with the convexity turned to the east. In the centre and near the apex of the curve, it presented a condensation of a reddish colour, similiar to that of clouds at sunset. The general appearance of the spot was that of a cirro-cumulus.
At 9.30am 40s there was heard a deep and very strong detonation, accompanied by many others not so intense, similiar to the noise produced by a large cannonball rolling along the upper storey of a house. This noise was very prolonged; it was found to last two minutes.
Meanwhile the vibration of windows and partitions (not the thick walls) was extraordinary and the rattling of panes of glass alarming. In some houses all the window-panes were broken.
Judging from the time which elapsed between the light and the sound of the first detonation, the meteor exploded in the air at a distance not less than 24km (15 miles) and this number is evidently too low.
Considering the aspect of the spot of smoke, it seems probable that the meteor proceeded from the SE towards the NW and near the zenith of Madrid it exploded.
Changed into smoke and dust, totally or partially, this smoke was carried away the upper currents of the atmosphere to the east. We find here a splendid confirmation of the theory which supposes that at the upper limits of the air, the wind moves from west to east.
The cloud continued its course to the ENE, dissolvong gradually away and at 3pm it was still perfectly visible like a light cirrus in the east some 20 degrees above the horizon.
The compression of the atmosphere at the instant of the conflagration was indicated by the registering barometers. In the aneroids, the trace is small but the mercurial one shows that the column rose 1.6mm and lowered 0.7mm, the amplitude of the total oscillation being 2.3mm
In the neighbourhood of Madrid, some fragments of the meteorite fell and I have obtained one of them. Externally the fragment is of a black metallic aspect; inside it is of white stony appearance, with somebrillaint points like nickel; it weighs 6.3mm grams.
From information received later; it appears that the phenomenon was visible in a large part of the Peninsula from Sierra de Estrella (Portugal) on the Mediterrnean coast and from Segovia to Aguilas or a distance of 700kms from E to W and 400kms from N to S.
Augusto Arcimis, Director of the Observatory.
It was speculated at the time that the bolide could have weighed as much as 130+kgs.