There are (were) basically two types of the acoustic guitar. One is the traditional nylon stringed guitar commonly known to have the "fan" bracing and to be the Torres style. It was developed by the Spaniard named Torres and the other more commonly recognised by the steel string version "X" bracing that a German named Martin originally designed. Both used gut strings prior to steel or nylon and the nylons came after WWII, (I believe, I may be wrong on the time) In the late 1800's as steel began to be commonly used, Martin was able to strengthen the X design and change. This is one of the reasons steel stringed instruments were more popular from late 1800's until WWII. You see many guitarist these days curl excess string on the peg. There is no need these days for it save laziness, the gut strings broke often and it paid to have the excess string there in reserve. Nylon and steel are not as week and can be replaced easier and cheaper.
and the Martin . .
I should check before I post I suppose, (my memory ain't what it used to be) but in this case I was correct.