The archtop guitar is often credited to Orville Gibson, whose innovative designs led to the formation of the Gibson Mandolin-Guitar Mfg. Co, Ltd in 1902. His 1898 patent for a mandolin, which was also applicable to guitars according to the specifications, was intended to enhance "power and quality of tone." Among the features of this instrument were a violin-style arched top and back, each carved from a single piece of wood, and thicker in the middle than at the sides; sides carved to shape from a single block of wood; and a lack of internal "braces, splices, blocks, or bridges . . . which, if employed, would rob the instrument of much of its volume of tone." But Gibson was not the first to apply violin design principles to the guitar. Guitar maker A. H. Merrill, for example, patented in 1896 a very modern looking instrument "of the guitar and mandolin type . . . with egg-shaped hoop or sides and a graduated convex back and top." The instrument featured a metal tailpiece and teardrop shaped "f-holes," and strongly resembled the archtop guitars of the 1930s. James S. Back obtained patent #508,858 in 1893 for a guitar (which also mentions applicability to mandolins) that among other features included an arched top, which were produced under the Howe Orme name. Another transitional design is the parlor guitar fitted with a floating bridge and tailpiece. These inexpensive instruments, manufactured by companies such as Stella and Harmony, are associated with early blues musicians. The earliest Gibson designs (L1 to L3) introduced the arched top and increasing body sizes, but still had round or oval sound holes.