Lancaster, PA and New York, N.Y. American Physical Society 1955. First Edition. 1059-1337, [1 blank] pages. Original blue/green printed wrappers. 7 3/4 x 10 1/2 inches. Previous owner name inked on upper right hand corner of front wrapper. Several scuffs and minor discolorations to the front panel. Light fading to the spine panel. Shallow bump to head of spine panel. The entire issue offered of The Physical Review Second Series, Vol 99 No. 4. Very Good. Wraps. 
The paper by Townes, et al. discussing the discovery of the Maser is found on pages 1264-1274. Offered in the original wrappers.
This work resulted in the Nobel Prize in Physics 1964 being awarded to Charles Hard Townes (1/2), and the other half jointly to Nicolay Gennadiyevich Basov (1/4) and Aleksandr Mikhailovich Prokhorov (1/4) "for fundamental work in the field of quantum electronics, which has led to the construction of oscillators and amplifiers based on the maser-laser principle".
"The first papers about the maser were published ... as a result of investigations carried out simultaneously and independently by Townes and co-workers at Columbia University in New York and by Basov and Prochorov at the Lebedev Institute in Moscow. In the following years there were designed a number of masers of widely different types, and many people made important contributions to this development. In the type that is now being mostly used the maser effect is obtained by means of the ions of certain metals imbedded in a suitable crystal. These masers work as extremely sensitive receivers for short radiowaves. They are of great importance in radio astronomy and are being used in space research for recording the radio signals from satellites." (Nobel Presentation Speech)
The Physical Review, The First Hundred Years, a Selection fo Seminal Papers and Commentaries, p.1165