Animals in german language

I'm sorry, but is is "Nashorn" with just one S. It means that the animal has a horn on its nose (Nase), so it is "Nashorn". "Nasshorn" sounds like "a wet horn", since "nass" is "wet". The difference is not only in writing but the pronunciation changes as well. If a vowel is followed by a double consonant, it is a short vowel, if it is followed by a single consonant, it is a long vowel. Example; "Ratten" (short a)= rats vs "raten" (long a) =to guess. I can't help it, I'm a native speaker of German and this difference is really important.