Book  (1937)  Page(s) 960.  
 
...In general, only a few really successful new roses occur in a population of several thousand seedlings. As an illustration of the odds against securing a really desirable new seedling when varieties are crossed, the following is quoted from an article by Hill (206) in the American Rose Annual for 1917:
From the 1914 crosses there were germinated over 2,500 seeds. Each little plant was given special culture, being planted in a bench where it received the same care as that required by the most important forcing varieties. In 1915 the first weeding out of the seedlings occurred, and by 1916 the 2,500 seedlings had been reduced to about 800. These were tested in blocks of five, receiving the most rigid attention and critical scrutiny. By the opening of 1917, the seedlings have been reduced to some fifteen sorts which Mr. Hill considers worth while going farther with. Of these fifteen several have been selected, named and registered, and propagation is proceeding with the idea of later dissemination.
From this group of 15 came: (1) Columbia, resulting from the cross Ophelia × Mrs. Shawyer; (2) Double Ophelia, from a cross between Ophelia and an unnamed seedling variety; (3) Rose Premier, from a cross between Ophelia and Mrs. Charles Russell; and (4) Mary Hill, from a cross between Ophelia and Sunburst. 

Book  (1936)  Page(s) 346.  
 
Hill, Mary (HT) E. G. Hill 1917; Ophelia X Sunburst; cream, center dark orange, very large, double, habit like Sunburst (improved).

Book  (1917)  Page(s) 143.  
 
Registration of New Roses in 1916
From E. G. Hill Company, Richmond, Ind.: Mary Hill. H.T. Ophelia X Sunburst. Of Sunburst type, improved in habit, foliage and growth, with immense bud and flower of cream color, with deep orange center.