First thing to try, assign it an address of 192.168.0.249, then "sudo reboot" and try to access it at 192.168.0.249 after a minute or two.
Next thing to try, set it up to automatically get an IP address assigned by your router. Make your interfaces file look like this, and your router should automatically assign it an IP inside your network. The important lines are bolded. Note that I have address, network, and broadcast commented out.
auto lo
iface lo inet loopback
iface eth0 inet dhcp
#address 192.168.1.50
netmask 255.255.255.0
#network 192.168.1.0
#broadcast 192.168.1.255
gateway 192.168.0.1
allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp