By adopting a sedentary way of life, the Neolithic groups increased their awareness of territoriality. During the 9600-6900 BCE period in the Near East, there were also innovations in arrowheads, yet no important changes in the animals hunted was detected.
3. Poor screen preparation is a major cause of pinholes. Particles of dirt, wood frame chips, and dust remaining on the fabric during coating will be trapped in the emulsion. Opaque, they will block light from hardening the emulsion beneath them, so that the emulsion in these small areas will wash away after exposure.
To adjust the contact points, a timing hole is located in the bottom of the frame next to the flange. There is also a mating hole in the shaft. Insert a pin (.093 6-penny nail) through the hole in the frame into the hole in the shaft. This locks the rotor in the position where the spark should occur.