Cranks are appliances to turn things round.  
A Crank that revolves¹ only half way will not always accomplish much of a change, and in many cases would only aggravate² the situation. Were it not for Cranks nearly all mechanical appliances would be motionless.
 
Men’s thoughts and opinions would all be the same, without some such device to get them out of the old notions, grooves³ and ruts in which they long have indulged and plodded⁴. The world has known Cranks ever since our first parents adopted the wearing of fig⁵ leaves, and Noah took up ship building on the weather bureau suggesting cloudy weather and showers in Eastern Turkey. Moses was a Crank when he forbid the eating of pork, salt water eels⁶, turkey buzzards,[2] owls⁷ and all other unclean birds, fish or animals of any kind, but there is no doubt that these commands were none of his mistakes.
 
Sacred writ⁸ gives a plenty of such characters, but, by skipping to times more recent, we find such Cranks as Copernicus, Galileo, Columbus, Newton, Franklin, and, during the last century, the Crank family has greatly increased with Daguerre, Watt⁹, Howe, Edison, Marconi and Tesla and scores of others, who, in some of the earlier times, would have been hung or burned as wizards and sorcerers.
 
Political, historical and religious Cranks have sprung up, turning over and upsetting many old-fogey and absurd notions and beliefs of the past.
 
In former times Cranks were the subject of ridicule¹⁰ and persecution¹¹ for trying to inject some new ideas into the public mind. History is profuse¹² with abuses of some of the best thoughts and discoveries that have come to the human race.
 
Supposing Copernicus had never advanced and enforced a conclusion that the Earth was round and revolved¹³ on its axis¹⁴, such motion causing the apparent rising and setting of the Sun. Only for this we might to this day believe in the story of Joshua’s command over the sun and moon, and associate believers with Parson Jasper that “De[3] sun do move.” It is pleasant to realize that we are living in a time when new thoughts do not frighten people, and we are not scared at what we cannot understand, even if it does not harmonize with antiquated¹⁵ ideas purporting¹⁶ to be 4,000 to 6,000 years old.
 
The humble¹⁷ and obscure individual who presumes to offer the few succeeding pages of crude ideas may be classed among pigmy Cranks, but, nevertheless, feels impelled¹⁸ to sow a little thoughtful seed on a subject that, to his knowledge, has never been discussed; and with a hope that such seed may some of it fall in good ground, and spring up a crop of criticism that may ultimate in some better mind taking it up and demonstrate with the success that the writer believes it merits.
 
To prove that the Earth was round required a long time and a serious amount of persecution. Now, to assume that it is hollow, may require more time than the brief discussion in this small book. Yet it is hoped the ideas here may take root in the enlightenment of the present day and start a growth productive of good fruit in the future. In order to discuss this question involves a task that in the outset may look discouraging, as follows:
 
The ax must be laid at the root of many[4] favorite and long accepted beliefs laid down by scientific authorities to explain the principal phenomena¹⁹ of disturbances²⁰ on and in the Mother Earth, and to overthrow²¹ nearly all accepted theories on the following subjects:
 
The assumption that the Earth is intensely hot or in a molten state in its interior;
 
The presumption²² that it is a solid ball;
 
The supposition that there is an actual pole;
 
That hills and mountains are always results of volcanoes;
 
That volcanoes are a prime or natural existence;
 
That living springs and lakes are results of surface influence;
 
The theories of the Gulf²³ Stream;
 
Icebergs²⁴ and the Ice belt, their formation;
 
Glaciers²⁵, how formed;
 
Equable condition of the Mediterranean²⁶ Sea;
 
And the Law of Attraction of Gravitation,
 
Or that the Sun is a mass of heat.