Studies of the possible X ray triple 4U1915-05

New optical observations of the X-ray dip and burst source 4U1915-05 were made. They are compared with new X-ray observations from Ginga. The optical modulation is at a period significantly longer than the X-ray dip period, and the stability of the optical period over approximately 2.5 years suggests it is the orbital period. The optical modulation is found to vary in shape on timescales of days but without significant color modulation. Comparison between 1916 and other systems are made. A discussion is given of a hierarchical triple model previously proposed to explain the dips, the optical modulation, and the long-term period.