(http://www.kansascyclist.com/img/news/Vintage-WichitaWheelmen.jpg)
What's so strange about this picture? Notice the make of the bicycles. The Penny Farthing was not, as you may have heard, the main precursor to modern bicycles: indeed, the "Dandy-horse" (http://www.studiolum.com/wang/games/dandyhorse/17k.jpg) was around long before. Increasing the size ratio of front to back wheels was an intentional adaption for the comfort of the rider.
(http://blog.krrb.com/wp-content/uploads/2013/04/tumblr_lv2uxhugTU1qzwdjso1_500.jpg)
By 1870, the designs of the boneshakers began to change with the front wheel of the bicycle being made larger and larger in order to improve the comfort for the rider. Originally known simply as bicycles or “high-wheels”, people began referring to them as “Penny Farthings” because of their resemblance of its wheel sizes to the largest and smallest English copper coins of the day. The Penny Farthings were expensive too and thus riders were mostly wealthy young men.