As far as I remember the vernier trick is choosing as a reference the line with a perfect match with the scale and then read the "fractions" scale.
Thats the trick. First find the "major" measurement & then look at the sub "tics" to get the minor sub division.
Allan Quatermain: “Automatic rifles. Who in God's name has automatic rifles”?
Elderly Hunter: “That's dashed unsporting. Probably Belgium.”