168 B. A, Newton— Fireball of January 13th, 1893. 



from the declinations in the sixth column we have the remain- 

 ders in the seventh column. These residues, taken strictly, 

 imply that the meteor path was curved a little, the concavity 

 being to the north. But if a great circle is drawn 15" north 

 of the one already computed as passing through the extreme 

 points it will represent the seven places with extreme devia- 

 tions of about 15". This is not greater than the average er- 

 rors of measurement from the plate as shown by the agreement 

 inter se of individual measures. A very slight curvature of 

 path is therefore indicated but is clearly not proven. 



27. Possible causes of curvature of path. — The effect of 

 gravity, and that of the rotation of the earth carrying the 

 camera, to produce curvature of path would be in the opposite 

 direction to, and for any reasonable supposition as to velocity 

 would be much smaller than, that indicated by the residuals in 

 column seven. If the meteor's light has the same refraction 

 as that of the stars there would be from this cause a small 

 theoretical curvature of path, since the starlight comes through 

 the whole atmosphere and the meteor-light only through a 

 part of it. But this cause too would furnish residuals very 

 small compared to those of column seven, and they would be 

 opposite in sign. If there is any curvature we may therefore 

 refer it to glancing in the air caused by the atmosphere's re- 

 sistance of the irregularly shaped body. 



28. Time at which the meteor appeared. — A number of the 

 observers say that 7 h 30 m was the actual or approximate time 

 of the appearance of the body. These were Mr. Noyes and 

 Mr. Kimball at Hingham, Mr. Harwood at Leominster, Mr. 

 Calkins at Branford, Mr. Grlenny at New Haven, Mr. Bradley 

 at Stevenson. Mr. Beale at Berlin says 7.35. Mr. Curtis of 

 Danbury placed it later than 7.30. Mr. Tower at Concord 

 says 7 h 40 m . As the time of the 75th meridian from Green- 

 wich is in use in the whole region there is no correction for 

 differences of local time. No one names a time earlier than 

 7 h 3o m . Probably there is a slight tendency to name a time 

 which is too late, since the ordinary observer of such a meteor 

 does not at once note the time, being interested in the appear- 

 ance of the body. Hence it is safe to take 7 h 3o m as not far 

 from the true time of appearance. It may easily have been 

 however two or three minutes later. 



29. Mr. Lewis's latitude in Ansonia was 41° 20' 40", and his 

 W. longitude 73° I 7 20". Allowing for precession, etc., 1 find 

 that the plane that passed through Ansonia and the path among 

 the stars as photographed by him cut the earth at 7 h 30 m in a 

 line which crosses the meridian of 73° 28 ; (that of Danbury) 

 at latitude 41° 25' 9". Each minute of time later than 7 h 30 m 

 would carry that point of intersection with the meridian of 



