The WiZard Collaboration cosmic ray muon measurements in the atmosphere

Balloon-borne experiments allow cosmic ray measurements to be performed over large ranges of atmospheric depths. The WiZard Collaboration is involved in a long-range investigation of the cosmic ray muon fluxes in the atmosphere. In this paper, we will discuss the relevance of such measurements to the atmospheric neutrino calculations and will review the results reported by the Collaboration, with particular emphasis on those coming from the latest flight CAPRICE98.