Polperro Postscripts

A blog for anyone with an interest in Polperro, publishing and people... with occasional musings on history and humanity.



Deck Prism

Posted on February 11, 2020

I was given this ship's prism by an American friend, Roberta Weisberg (see blog January 2016). At first, I wasn’t sure what it was… my first thought was that it was a paperweight of some sort. The smooth, hexagonal face measures three inches between opposing vertices, and three inches between opposing sides. The overall height to the tip is three inches. It is quite heavy for its size, and I'm not sure exactly how old it is.

What I have since found out was that for centuries, sailing ships used deck prisms to provide a safe source of natural sunlight to illuminate areas below decks. Before electricity, light below a vessel's deck was provided by candles, oil and kerosene lamps - all dangerous aboard a wooden ship. The deck prism was a clever solution: laid flush into the deck, the glass prism refracted and dispersed natural light into the space below from a small deck opening without weakening the planks or becoming a fire hazard. Aboard colliers (coal ships), prisms were also used to keep check on the cargo hold: light from a fire would be collected by the prism and be made visible on the deck even in daylight.

In normal usage, the prism hangs below the overhead and disperses the light sideways; the top is flat and installed flush with the deck, becoming part of the deck. A plain flat glass window would just form a single bright spot below - not very useful for general illumination - hence the prismatic shape.

Another Man's Shoes

Posted on January 16, 2020

Stories of extraordinary heroism by people caught up in the horrors of the Second World War are still emerging even seventy-five years after the events.


One such is the first-hand account of Sven Somme, a Norwegian scientist who was working for the resistance movement in 1944 when he was arrested for spying by the Gestapo. On his way for interrogation and almost certain death, he managed to escape and make his way across the mountains to freedom in Sweden, pursued by German soldiers.

Sven’s remarkable story, written shortly before he died after the war, was eventually published by the Polperro Heritage Press in 2005 after his daughter Ellie Somme had returned to Norway and traced the route of her father’s flight from Nazi-occupied Norway, meeting some of the families who had helped him along the way.

Ellie recounts one particularly emotional moment when a pair of her father’s shoes, which he had exchanged for mountain boots, were returned to her by one family who had sheltered Sven along the way.

After the book, Another Man’s Shoes, was published fifteen years ago, Ellie later discovered coded messages hidden in microdots under postage stamps on some letters among her father’s effects. Much has subsequently come to light about the secret work of the brave men and women who worked for the Norwegian resistance, many of whom were tortured and executed following capture.

Ellie Somme talks about her father’s work on BBC Radio 4 Saturday Live on 18th January. 

The surviving ledgers and letterbooks of Zephaniah Job, the ‘Smugglers’ Banker’ of Polperro, include an exercise book that had once belonged to a boy named John Clements, one of Job’s pupils when he earned a living as a schoolmaster shortly after arriving in Polperro in the early 1770s

The brown covered book, measuring 6in x 9in, is inscribed on the first page: John Clements of Polperro and, underneath a multiplication table, 12th December 1775. John Clements was born in 1768, so would have been seven years old at the time.

Subsequent pages (there are some 70 in all) mostly contain a series of arithmetical problems and exercises and, towards the end, tables of weights and measures, all written in copperplate hand. These not only provided a fascinating insight into the educational methods of the period, but also reveal something of the trade carried on in Polperro in the eighteenth century.

If one anker of Brandy costs £2..6s..9¾dwhat shall 3 ankers cost at that rate?

If one yard of Broad Cloth cost £17s..10½d what shall 4 yards cost?

If I buy One Sheep for £12s..9¼d how much must I give for 7 sheep?

If one anker of Geneva costs £2..18s..7½d what shall 18 ankers cost?

What shall 72 ankers of Rum, each 10 gallons, cost at 4s..9¾d?

Others shed some illuminating light on earnings and the cost of living at the time:

If my yearly income be £36..16s..8d how much will it be for 7 years?

If I pay 5s..7½d for the wages of 6 men for one day, what must I pay them for 12 days?

But several of the calculations set out in the exercise book seem almost impossibly challenging even for an adult mathematician, let alone a seven-year-old boy:

Reduce 7842 miles into barleycorns  [a barleycorn = one third of an inch];

Answer: 1,490,607,360 barleycorns!

­­­­­­­­­­­­­­­­­­­­­­­­­­­­How many barleycorns will reach round the globe, it being accounted 360 degrees, each degree 60 miles?

The answer is a mind-boggling 4,105,728,000! But, as Perrycoste himself pointed out, the task ‘seems calculated to reduce one’s brain to flitters’.

How many wagons will reach from Fowey to Looe, it being computed 8 miles; allowing 6 yards for the standing of each wagon?

Reduce 12 years, 11 months, 3 weeks, 6 days, 5 hours, 48 minutes, 57 seconds into seconds

How many seconds are there in 38 solar years?

[A solar year in the 18th century = 13 months, 1 day and 6 hours. Today it is 365 days, 5 hours, 48 minutes and 45 seconds]

There are several other exercises involving units of weight from the old avoirdupois system such as grains (1/7000th of an ounce), drams (1 dram =  1⁄16 ounce) and scruples (1 scruple = 16 grains). For example: Reduce 41,423,103 drams into tuns [1 tun = 216 gallons].

John Clements obviously kept his school exercise book because, in later years between 1787 and 1808, he used some of the blank pages at the back for accounts on the schooner Polperro of which he was master. There are one or two entries relating to dealings with William Quiller involving quantities of rum, brandy and Geneva which suggest that he also joined the smuggling trade in contraband goods from Guernsey.