Free Cross of Fire by Mark Keating Page B

with eyes more firmly on the pot than the instruction.
    ‘Very well,’ Coxon said. ‘But for Cape Castle we will use the rhumb lines of a Mercator projection. I have all the readings I need for such a course. Do you have Moll’s map of Africa?’
    Herman Moll’s 1720 map was as yet the most detailed description of the continent. Gibraltar at its tip, part of Brazil at its left side and Madagascar and the Amirantes to its right. But it had no rhumb lines. The rhumb lines, the loxodrome spider-web patterns that criss-crossed mariners’ Mercator charts were paths for ships to tread. But the Moll map served more as a land map than nautical chart, its detail for the coast exceptional to this end. Manvell rustled through his papers until he found it.
    ‘Good,’ Coxon said. He put down his coffee and picked out of Manvell’s collection a parallel rule, the compass card, divider and pencil, then with a sweep of his sleeve like a broom sent the rest to the floor. Manvell jumped at the sudden crash.
    ‘Does that offend, Lieutenant? I was beginning to accept that such disturbance was common in my cabin.’
    Manvell watched his compasses dance on the floor like dreidels. A thousand images of their new imperfections spinning through his brain. Earnestly his voice was shamed.
    ‘My apologies, sir.’
    ‘The map to the table.’ Coxon cleared his coffee to a safer surface as Manvell set the paper.
    ‘Now, with no rhumb lines, and just Moll’s single compass rose, I want you to chart me a course from Cape Vert point – an easy start for it sits on the fifteenth parallel, is easy to sight and with the Verdes to our starboard you’d be a fool to not know where you are in the world – all the way to Cape Coast Castle. If you please, Mister Manvell.’
    Manvell began to sit.
    ‘How long do I have, if I may request, sir, to measure my aptitude?’
    Coxon took up his coffee.
    ‘Until I finish this , Lieutenant.’ He took his first sip.
    Manvell did not take a seat.
    The dividers first. He took the nautical mile reading from the latitude scale down the side of the map and set the legs; three attempts, his fingers unable to steady and Coxon on his second taste.
    Manvell marked Cape Vert, a nice neat hook like a parson’s nose hanging off the coast as if God had created it just so for mariners to mark.
    Taking up the rule and pencil he drew, assured and swift, a line through the archipelagos and past the Grain Coast, his second mark. Next he walked the rule to the rose near the edge then replaced the rule with his compass card and penned the bearing in the map’s margin. Next, he swiftly brought back the rule and drew again, traversing into the Gold Coast and Cape Castle clearly marked amongst the other factories. His third mark.
    He walked the rule back to the rose, its hinge treading the way like pigeon steps and again with the compass card took and wrote his second bearing as Coxon’s cup lifted higher.
    Provident that he had set the divider first. He danced it along the lines with one hand and pencilled his calculations with the other, dropping the brass instrument the moment Coxon placed back his cup.
    ‘Well?’ Coxon wiped his top lip. Manvell resisted wiping the shine from his forehead.
    ‘I believe, Captain, that from Cape Vert, south-east by south at thirty-five degrees for ninety miles. Then east by north for seventy miles, eighty-one degrees into Cape Castle.’
    ‘And if we maintain four knots from Cape Vert? You have us at how many hours?’
    ‘Forty-eight hours at twenty-four hour sail . . . if we are in need of urgency with our post, that is.’
    Coxon looked down at the pencil marks and scribble that scrawled in their anxiety to finish; the numbers and letters falling over each other.
    ‘Good. Good. Although I prefer Waghenaer’s projection.’
    Lucas Waghenaer, the Dutch cartographer who gave the seaman the term, ‘Waggoner’ for his collection of charts.
    ‘Far before your time but good sense to rely