Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 59).In this thesis, a muon telescope is setup in order to measure the zenith angular distribution of cosmic ray muons at sea level. The setup consists of two long scintillator counters with double-ended readout. Previous measurements have shown that the intensity of muons obey the cos 2 0 distribution. In this thesis, two methods are used. The first method is by rotating the whole setup to point at the zenith angle under measurement. The second method is by time of flight measurement. With the double-ended readout, the position of the muon pass through can be reconstructed from the time difference between the two ends. Therefore, the paths of muons can be also reconstructed. Both measurements confirmed the cos 2 0 distribution, with 'tails' at large zenith angles, which is also found in previous measurements.by Yi-Hong Kuo.S.B