The formula for open-circuit output voltage of Blumlein circuit has been obtained by solving the differential equation of the circuit. The approximate formula for open-circuit output voltage of the Blumlein circuit presented by W. A. Fitzsimmons and the authors of "Laser designing basis" is modified. The circuit parameters affecting the increase of peak pulse power of the device have been found. The conclusion of the paper "The N2 lasers"is rectified. The expression for open-circuit output voltage of a capacitor transfer circuit is given.