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The above is one of the sets of observations made by Major Robinson at St. Helen's Island, Upper Canada, in 1845. Reference was always made to the particular transit and chronometer used; stating also if the error of collimation had been determined, and the transit levelled immediately before the observation, and whether the east or west end of the axis was illuminated.
In the transit books used on this occasion, made of four or five quires of letter paper bound up in a strong cover, the right-hand page was printed in the above form, leaving the other blank for recording levels, calculating the azimuthal errors, &c., &c.
The form for registering transit observations in a permanent Observatory, is of course different from the above: that at present in use at the Royal Engineer Observatory at Chatham, taken from the "Corps Papers," is given as an example.
The quantities opposite the different numbers of hours, minutes, and seconds, are to be subtracted, to obtain the equivalent interval of mean solar time for any period.
The quantities opposite the different numbers of hours, minutes, and seconds, are to be added, to obtain the equivalent interval of sidereal time for any period.-Vide Table of Equivalents, page 489 of the Nautical Almanac. This table, and the preceding, are calculated from the ratio of a sidereal to a mean solar day-twenty-four hours of mean time being equivalent to 24h 3m 568:5554 sidereal time.