- Quernstone
Stones developed for the grinding of grain.
As humankind ceased to live as nomadic hunter- gatherers and began to settle down and raise crops, a different style of tool became necessary. People were now able to grow grain. However, grain had to be ground into flour in order to make bread. To accomplish this task an early form of mil, called a quernstone, eventually emerged.
Approximately 4000 years ago, humans worked out that they could place one rough stone on top of another and use the two of them to grind grain into small particles. Early versions consisted of a rough rock base, or quern, and a smaller rock that could be ground over the top of it, often referred to as a rubbing stone.
A major advance occurred when the top stone was made to turn on the stationary bottom stone rather than move parallel to the long axis of the stone. These so-called “rotary querns" eventually evolved to feature a central hole in the upper stone that would allow grain to be poured in from the top and flour to work its way Out from between the two stones. Later societies experimented with using c
stone-the Romans favoring types of lava for their rough and sharp surfaces.
The quernstone evolved into larger water- and wind-powered mills, but is still in use in societies where grain is ground by hand.
SEE ALSO: GRANARY, WINDMILL, WATERMILL, TIDAL MILL, AUTOMATIC FLOUR MILL
- Rivet
The humble rivet may be small, but is has a lot to answer for including, quite possibly, the sinking of the Titanic. Rivets have been in widespread use for thousands of years but, because engineers now depend on them to secure boats, bridges, aircraft, and other more complex constructions, their reliability has become paramount.
Rivet holes have been found in Egyptian spearheads dating back to the Naqada culture of between 4400 and 3000 B.C.E. Archaeologists have also uncovered many Bronze Age swords and daggers with rivet holes where the handles would have been. The rivets themselves were essentially short rods of metal, which metalworkers hammered into a pre-drilled hole on one side and deformed on the other to hold them in place. Today, a wide variety of rivets exist, as do specialized tools for installing them.
The extensive use of rivets in modern engineering and architecture has, inevitably, increased the likelihood of the odd one or two coming unstuck. Materials scientists have blamed rivets for RMS Titanic's infamous descent in 1912, killing over 1,500 people. Jennifer McCarty and Timothy Foecke carried out an in-depth study of the sunken wreck and concluded that shoddy workmanship had sent her to the ocean floor. More specifically, a large proportion of the three million rivets driven into the ship were made with substandard iron when, McCarty and Foecke claim, they should have been made from steel. The weaker iron rivets used at the front of the Titanic, where it struck the iceberg, were unable to withstand the stress of an impact, as the steel rivets used in the body might have done.
SEE ALSO: WELDING, WROUGHT IRON, SCREW, NAIL, CLAW HAMMER