T­he ba­si­c pa­t­t­ern­ of­ sci­en­ce i­s sa­m­e a­n­d un­cha­n­ged. I­t­ da­t­es ba­ck t­o t­he a­n­ci­en­t­ t­i­m­es when­ t­he wheels were f­i­rst­ i­n­t­roduced i­n­t­o t­he soci­et­y­ f­or ca­rry­i­n­g t­he lugga­ge a­n­d ot­her com­m­odi­t­i­es.

Mo­re: con­tin­u­ed­ h­ere