PREFACE. 
To put into the hands of young persons the scientific 
works from which the following information has been 
gleaned, and to expect them to understand them, would 
he very much like giving a labouring man the Greek 
Testament, and expecting him to read it. The difficulties 
in the way of arriving at the meaning of obscure 
sentences, the having to pick the thread of facts from 
a tangled skein, and to write them into a clear and 
connected narrative, those only can know who have 
made the attempt. Whether the attempt in the present 
case is satisfactory, remains with the public to decide. 
Norwich , May, 1860. 
