The Taropatch, (the name comes from "Taropatch Fiddle" and early Hawaiian slightly derogatory name for all Ukuleles as it was used by the "Landed" Anglo Settlers to describe the instruments played by the Portuguese indentured labour as they worked the taro fields), with its 8 strings in 4 courses, is a very traditional string configuration dating back to the birth of the Ukulele itself. The idea of the extra strings is to give a more plaintive, slightly chorus like tone; and possibly to add volume. Manuel Nunes and his family were certainly fond of them and made quite a few. Martin then picked up on them and brought them firmly to the Mainland. Initially they were only moderately successful on the Mainland as gut strings and double the tuning problems made them tricky to play. Their biggest influence on early Ukulele development though was, originally they were all what is now Concert scale and a number of the more professional players of the time liked this extra size for the extra volume and so played them with only the 4 strings. This led to Martin producing a 4 string variant and the Concert scale was born. 

These days with nylon strings and digital tuners, tuning is not so much of an issue, - for the record the Taropatch today, (there were probably lots of different tunings used originally, including the Violin/Mandolin tuning and the Cavaquinho tunings; plus with primitive gut strings all of the courses would probably have been in unison), should be tuned so the E and the A are doubled on the same pitch with the G and C doubled an octave apart so gG~cC~EE~AA - and the plaintive tone is quite nice. 

Another change from the original in today's Taropatches is the Tenor scale is more popular and most of them are Tenor. There are still some Concerts made however, and Baritones too, (though for the Baritones the tuning is usually dD~gG~BB~EE and I have heard of all of the strings being an octave apart). You can even see, though it's mainly for the novelty value, Luthier made Soprano, and even Mini scale Taropatches?