horizon through the Pleiades up as high as the head of Medusa. Left off with β Tauri. Afterwards I continued with horizontal sweeps till daylight was too strong for seeing any longer.
1792. May 3rd.—My brother having desired me by way of practice to settle the stars α Persei and Castor, and α Virginis, by some neighbouring stars in Wollaston's Catalogue, I made last night an attempt to take their places. The moon was near the full, therefore no sweeping could be done.
1795. May 1st.—Mem. In the future when any great chasms appear in my journals, it may be understood that sweeping for comets has not been neglected at every opportunity which did offer itself. But as I always do sweep according to the precept my brother has given me, and as I often am in want of time, I think it is very immaterial if the places where I have seen nothing are noted down.
Nov. 7th.—0.40 sidereal time. About an hour ago I saw the comet [seventh] which is marked in the annexed field of view [diagrams drawn with extreme neatness illustrate the entries when necessary]. When I perceived it first the two small stars were entirely covered by it, and it appeared to be a cluster of stars mixed with nebulosity; but not knowing of such an object in that place, I kept watching it, and perceived it to be a comet by its having moved from the two small stars, so as to leave them entirely free from haziness.
1797. Aug. 14th.—C. H.'s comet. At 9.30 common time, being dark enough for sweeping, I began in the usual manner with looking over the heavens with the naked eye, and immediately saw a comet nearly as bright as that which was discovered by Mr. Gregory, January 8, 1793. I went down from the observatory to call my brother Alexander,L 2
