Monthly report for May 1998 by Christian A. Hummel: CAH submitted the paper on NPOI observations of Mizar A and Matar to the Astronomical Journal. CAH reviewed a paper for Nature. CAH fitted orbits to combined speckle and NPOI data of the binaries Kap UMa, Sig Her, and 1 Gem. CAH mapped Mizar A at 23 epochs and produced a movie sequence using AIPS.