Rev. C. S. Lyman on the Auroral Bow of June, 1852. 59 
Unfortunately for the purposes of comparison, the times indi- 
cated in the observations given above, with the exception of Mr. 
Herrick’s, are uncertain to a considerable amount. Those for 
Windsor may be in error ten or fifteen minutes. Professor Brock- 
lesby, from subsequent comparison with a church clock in the 
city, supposes his time to be not far from correct. In respect to 
indsor, this uncertainty is much diminished by the fact, that 
both at that place, and at New Haven, the bow was observed till 
it finally vanished. Its disappearance at both places was rapid, 
and in circumstances somewhat similar. It will perhaps be allow- 
able, therefore, to correct Mr. Watson’s time from that at New 
Haven. If eleven minutes, (which is about what Mr. Watson 
Supposed his. watch may have been too slow,) be added to the 
former, the appearances of the bow at the two places are very 
readily comparable with each other. It may be remarked also, 
that the more definite observations at these places were made 
within a few minutes of the disappearance of the bow. ‘The 
times noted by Mr. Hyde appear to be given in round numbers, 
and are consequently of less value than those of Mr. Watson. — 
From the observations at New Haven and East Windsor, it is 
easy to lay down on a celestial globe the position of the belt as 
Seen at very nearly the same time from each of these places. 
This cannot be done however as definitely as is desirable, on ac- 
Count of the rapid southerly motion of the belt, and the varying 
veXtres in some parts of it. ‘The position of a part of the bow 
hear the meridian, as observed by Mr. Herrick, changed as much 
as four or five degrees in less than a minute. As seen from 
Windsor the average motion appears to have been much slower, 
at. least in that part of the belt near Arcturus. Nine minutes after 
at star was in the southern border of the belt, it is meritioned 
as being in the center-of it, and eight minutes afterwards, in the 
horthern border. ; ogee Poe 
. Ou thus laying down the positions of the bow on’a globe ad- 
Justed to the hour of the day, its parallax, as seen from the two 
named, is very obvious. Even if we allow an uncertainty 
of several minutes in the times, avd compare Mr. Herrick’s latest, 
or Most southerly position, with Mr. Watson’s earliest, or most 
northerly, there is still left a parallax, though quite small. And 
if, on the other hand, we compare Mr. Herrick’s earliest with Mr. 
Watson’s latest position, the parallax, for the center of the belt, 
cannot be made to exceed fourteen or fifteen degrees at most. 
_ Making the most probable correction for the times, and obtain- 
mga ean position of the belt on the globe for each place, we 
&stimate the altitude of the bow, ina plane perpendicular to its 
8eneral. direction across the heavens, to be 72° for its southern 
edge, as seen from New Haven, and 74° for its northern; at the 
: 
chee = aby, 
‘ 
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. 
