Here is a very simple script written in Python. It downloads all the images of one or several books into the directory where the script is. Unfortunately WordPress does not allow to upload the script (either in .py or .txt), so here it is. → are for indentations.
Remember that, depending on the content set (see here), the images are either in .tiff or in .jpg.
#set the list of books you want to download. For this script, we start from each book's first page, i.e the book id+00010
idlist = ['012000180000010',
for i in idlist:
→while int(i) <= end :
→→url = "http://callisto.ggsrv.com/imgsrv/Fetch?recordID="+str(i)+"&contentSet=ECLW"
→→→req = urllib2.Request(url)
→→→req.add_header('User-agent', 'Mozilla 5.10')
→→→dl = urllib2.urlopen(req)
→→→with open(str(i)+'.tiff', 'wb') as f:
→→→→→content = dl.read()
→→→→→if not content: break