This is the first attempt at visualizing the shape of a time machine. These are all constructed and based on machines from the Industrial era, with a bit of a fantasy feel. As I'm trying to move away from Steam-punk I envision them all running off Diesel fuel and electricity. Some of the silhouettes suggest there being a capsule where the time traveller would climb into, whilst a couple would have a seat on them. I expect I'll be looking at other themes as well as improving these.
Consider how the machine meets the floor, Sam - these silhouettes are exciting - but there's something a bit lumpen about their bottomhalves - maybe think a bit more 'boaty' somehow - and also maybe palanquins:
http://unitproj.library.ucla.edu/special/wildershores/images/SheldonPalanquin_small.jpg
I'm sure you've seen this already - but this might help too:
http://www.youtube.com/watch?v=vORsKyopHyM
I agree with Phil Sam. I would also suggest a trip to the Science Museum in London. First hand research would really help in this case.
One other avenue would be to look more at the history of clocks / time - taking the work TIME in to consideration alongside Machine (you have machine above). There are some very bizarre early clock designs out there. One of them may inspire a different rationale for understanding the concept of time. May be a trip to the Greenwich too?
*work = word
Think of the 'representation of time' as a possible way in.
http://3.bp.blogspot.com/_DW3Bp12L7YI/SoGd70LswGI/AAAAAAAAaq4/2Q6FffxPK8c/s400/image002.jpg
http://photos.travellerspoint.com/108415/Strange_cl.._Prague.jpg