Monthly report for April 1998 by Christian A. Hummel: I have finished the paper on Zeta 1 Ursae Majoris and Eta Pegasi, and submitted it to the editorial board. Following the conference on "Astronomical Interferometry" in Kona, HI, I have written a 10 page contribution to the proceedings. For a USNO news release and a news note in Sky and Telescope, I have prepared a color composite image and description of the new Zeta Orionis A binary.