May 29th 1889
I herewith enclose reply to your letter of March 31st 1889. Mr Pottack who made the observations finds that a clerical error of hour was made on May 20 which accounts for the error in the first place.
In May 6 the mean rate of comet’s motion had been taken and hence the error. On June 11 the difference in declination between comet and star was taken by declination tangent screw and afterwards found faulty. On June 13 no error can be discovered.
I regret that these errors should have crept into the work. at the time I was too much engaged with other duties to examine the work before it was sent out.
Yours very truly
H. C. Russell