To fill the need of a new deflection determination and to provide a more accurate value, a new measurement of $\frac{e}{m}$ is being made. The method used was conceived by Professor E. O. Lawrence. The essential points of the method are: acceleration of electrons to a continuous range of velocities by a radiofrequency electrostatic field, choice of a particular velocity by magnetic field resolution, measurement of this velocity through radiofrequency fields applied to a pair of accelerating slits and a pair of decelerating slits. A most important advantage of this method is that no acceleration voltage need be measured. This, combined with other properties of the method, practically eliminates errors due to contact potentials. Another advantage is the very high observational precision the method makes possible. The present results, although not considered final, are of an accuracy comparable with published values. The value obtained from two groups of observations made at different electron velocities (the corresponding electron voltages being about 1420 and 844 volts) is $\frac{e}{m_0}=(1.7571\mathrm{}\pm 0.0015)\times {10}^7 \mathrm{e}.\mathrm{m}.\mathrm{u}.\mathrm{}$ The uncertainty stated is a conservatively calculated probable error. A comparison of six recent and probably most reliable $\frac{e}{m}$ determinations is made. The spectroscopic and free electron averages are now in good agreement. The weighted average of these six determinations is $\frac{e}{m_0}=(1.7598\mathrm{}\pm 0.0005)\times {10}^7 \mathrm{e}.\mathrm{m}.\mathrm{u}.\mathrm{}$

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