14 
A PREFACE AND AN APOLOGY. 
the dragon-fly, conftruding them of reeds for the nervures, 
and calico for the membranous covering. 1 
There are fome old boys now living who remember 
the advent of india-rubber balls , and their marvellous power 
of getting high up into the air, beating the old parti¬ 
coloured leather-covered fellows “ all hollowand with 
the ideals of fuch india-rubber performances in a boy’s 
brain, nothing was eafler or more natural, when the an¬ 
nouncement came that india-rubber Jhoes were in the 
market, than for him to fancy that, with a pair of thefe 
on his feet, leaping five-rail fences, or even ten, would be 
a trifling paftime. My father aflured me I was miftaken, 
and would be difappointed; but I faw myfelf fo plainly 
in the air, bouncing up on india-rubber fhoes, that nothing 
but india-rubber fhoes would pacify me, and they were 
bought. I could hardly reftrain my childifh impatience; 
but inftead of finding myfelf ten feet high in the air, I 
found myfelf twenty feet deep in the flough of difap- 
pointment and chagrin: my india-rubber fhoes wouldn’t 
bounce me a bit! Ah, thofe fhoes! I fhall never forget 
them. But who is there that has not had his india-rubber 
fhoe experience ? Alas for the vifions of childhood! 
Alas for the ideals of youth ! 
1 There is nothing fo fatisfadtory or delightful to an inventor as ideal me-, 
chanical conftrudtions; all the parts are fo perfedt, move with fuch precifion 
and with no fridtion; and then, too, everything comes out exadlly in accordance 
with your theory. 
