Sunspot and geomagnetic-storm data, derived from Greenwich observati ons, 1874-1954 / 
compiled under the direction of Sir Harold Spencer Jones. 
 - London :  H. M. Stationery Off. ,  1955. 
 - viii, 106 p. :  ill. ;  31 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Magnetism, Terrestial--Observations.<br/>Sun-spots.
<br/><br/><label>Dewey Class. No.: </label>Q 523.774 GRE