According to Alred Frankenstein the horizontal drawing comes from: One of the sketchbooks which Harnett filled with designs for engravings on silver in his days as a silver craftsman, before he took up painting, around 1868. It was probably intended for the outside of a silver bowl or ornamental cup.
The vase in the still life sketch at the lower left also appears in an undated but extremely early painting by Harnett, no. 1 in my catalogue of his works, but the relatively free style of the drawing suggests that it is a study for a later still life using the same model; the date should be 1879 or thereabouts.
The subject matter of the sketch at the lower right indicates that it was done during Harnett's years in Munich, 1881-1884.