What happens next in this paragraph?

How to make a galvanometer 
Select a compass. 
A compass has a magnetic needle. This needle will allow you to detect electrical currents because electrical currents generate a magnetic field (and this field interacts with the needle).
Options are:
 -- A compass device is ideal for all sizes. It should not be too small or too small to allow you to move the compass around for a long time..
 -- The most effective compass will be one meant for navigational purposes (i.e. designed to align to the earth's magnetic field and point north), rather than a toy..
 -- Consider your compass's specific orientation to determine what direction to see radiographic instances of direction you want your galvanometer to follow. The magnetic needle will determine the direction of the galvanometer that you choose..
 -- A good rule of thumb is to use a compass that is at least 50 volts, although some others require 20 volts. Use a compass that you can easily recognize..
The most effective compass will be one meant for navigational purposes (i.e. designed to align to the earth's magnetic field and point north), rather than a toy.