did you copy the index.htm file into the sd card first then try to see if the web server is working by going to
http://192.168.1.208:8000
The curl upload is for when you box up your project and you don't have access to remove your sd card from the ethernet shield. You can use it, but at least test first of the webserver code works.
Note that the program will stop if it does not detect temp sensor and ph sensor. If you do not have any of these and you want to test the webserver, you can comment out that part of the code and test.
The program will sound one beep at the start. If you hear two beeps at the end, then everything started up ok.