Positive ground depends upon proper circuit functioning, which is the transmission of negative ions by retention of the visible spectral manifestation known as "smoke". Smoke is the thing that makes electrical circuits work; we know this to be true because every time one lets smoke out of the electrical system, it stops working.

This can be verified repeatedly through empirical testing. When for example, the smoke escapes from an electrical component (like,say,a Lucas voltage regulator), it will be observed that the component stops working. The function of the wire harness is to carry smoke from one device to another, when the wire harness "springs a leak" and lets all the smoke out of the system, nothing works afterwards.

Starter motors were frowned upon in British motorcycles for some time, largely because they consume large quantities of smoke, requiring very large wires. It has been noted that Lucas components are possibly more prone to electrical leakage than Bosch or generic Japanese electrics.

Experts point out that this is because Lucas is British and all things British leak. British engines leak oil, shock absorbers and hydraulic forks and disc brakes leak fluid, British Tyres leak air, and the British defense establishment leaks secrets...so, naturally, British electrics leak smoke.

From the basic concept of electrical transmission of energy in the form of smoke, a better understanding of the mysteries of electrical components--especially those of Lucas manufacture--is gained by the casual user.