To save download time, our etexts are stored in zipped form as well as text form. Zipped files are smaller, and take less time to transfer to your computer, but you need a program to unzip them. If you try to view a zipped file directly, it looks like gibberish.
You can recognize zipped files easily because their filenames end in .zip.
If this happens, either make sure you're asking your browser to Save the file rather than display it (often, you right-click the file and choose Save) or else click on the version of the file that ends in .txt instead of .zip. You don't need a zip program to view .txt files.
Looking at a zip rather than a text file is by far the most common reason for this problem, but there are some others. If you're quite sure that you're not looking at a zip file, then it could be that the file you downloaded is in a character set that your viewer doesn't recognize, like Big-5 [V.78] for Chinese texts, or Unicode [V.77]. If this is the case, you will have to find a viewer that works on your computer for the specified character set. We may also have an ASCII version of the same text available for you--we do try to have ASCII versions for everything [G.17], but some languages, like Chinese, just cannot be sensibly expressed in ASCII.
If you can see most of the characters, enough to be able to make out the text, but there are regular gibberish characters, black squares, empty boxes or obviously missing characters scattered about through words, then you are probably looking at an "8-bit" text [V.79], with accented characters, and your viewer doesn't handle the character set. See the FAQ "I can read the text file, but a few characters appear as black squares, or gibberish" [R.31].
If there are a very few gibberish characters, black squares or obviously missing characters in the text, then it's likely that this was intended to be a 7-bit text, but a few 8-bit characters like the British pound symbol or accented letters slipped through.