Monday, 13 December 2010

Tom Critchley to Mary Platt 13.12.1940

My dear Mary,

We'll tackle Mollie's question about sulphuric Acid first. As a matter of fact we don't make sulphuric acid & the firm who supplied us with that acid & nitric acid as well was wiped out of existence, their works are in such a state that they are now looking for a new site to start again; sometimes Jerry does do some real damage.
Sulphuric acid is made, either direct from sulphur or pyrite or as a by-product in the coal gas industry. In either case, it is made by oxidising sulphur-dioxide to the trioxide, dissolving the latter in water & concentrating by evaporation.
S + O2 = SO2
2SO2  + O2 = SO2 =  2SO3
SO+ H2O = H2 SO4
4 Fes2 + 2202  = 2Fc O + 8SO2 

The difficulty is the oxidation of the SO2 . In the old days this was done in lead chambers (as they did at Hardshaw Brook in the chambers along the Warrington New Road). A little nitrogen per oxide was added to the mixture of SO2  & air, leached with water & so it went on slowly oxidising. Of course SO2  is slightly soluble in water, but nothing like to the extent that SO3 is. The modern process does away with the old bulky lead chambers and speeds up the process of passing the air & SO2  mixture through the platinised asbestos (platinum in a very fine state of division mixed with an asbestos pad) The platinum acts as a catalyst & without taking any final part in the reaction accelerates it.
I'm afraid I can't go into the details of the processm you'll find it in any decent chemistry book. If the query was how could Mollie make it? she can't with any hopes of success. It's easy enough to make the sulphurous acid, but the snag is oxidising it to sulphuric though I suppose it could be done in the lab with hydrogen peroxide. Anyhow SO2  isn't nice stuff for chesty folks, it invariably stops my chest up.
Talking of Sulphuric acid our tank in the works is 14 ft up on a gantry & holds 7 tons. A bomb fell alongside it, blew the tank up in the air & dropped it back onto its own base, but twisted the girders into fantastic shapes.
You wouldn't believe it, but now Jerry gives us some nights off, we feel his visitations more than when he came every night. Looking back it seems surprising how we stuck it, perhaps the feeling that it was inevitable or the excitement helped us.
Anyhow, he has come back to his old love & even last night when he went to Sheffield, had to go via this place. He was roaring about all night, but as we are used to his tricks by now, we soon realised it wasn't our raid, so could treat it like we would a bad thunderstorm.
Sunday night wasn't too bad, except we tried in vain to get to sleep. As I lay in bed half asleep it sounded at times as if the ceiling was coming in. All around the works he dropped large numbers of incendiaries, 30 in one factory and 36 in another. The Cosmos lamp works got badly singed, our place escaped with one which was very quickly dealt with, but there were fires all around.
Wednesday night or rather about 6.00am on Thursday morning (the raid was on for 14 hours) 6 bombs dropped on East Barnet all around our old house in Somaford Grove & lots of folk here have had to evacuate as several haven't gone off. It's a mad world. You would have thought so looking out the other night with a beautiful clear sky & bright moon & gun flashes all around & the devil up above wondering when to press the button & blow somebody to blazes.
One only hopes the other places hold the front line as well as London has held their section.
It's no good jawing Seth, he will please himself, but I think it is a great pity & both he and Biddy will regret it later. I wonder if Ada has had anything to do with it.
We've just had a letter from Ronald written just before he went on his Trans Jordan holiday. They hired a big car, and as they had to travel over the desert, took food and spades with them. No you are wrong, the spades weren't to eat the food with, they were in case the car got stuck in the sand. He is having a good time.
That's all this week, unless I've something to add tomorrow, which I doubt, as the weather is foggy & the roads are icy & bad for poor motorists. It all helps to make the war more pleasant!!!
Love to you all from us both,


PS don't swank, we got a pound of onions one day & sometimes we get eggs. Between ourselves I can scrounge enough butter to just keep us going.
PPS Somaford Grove is now roped off as there is a time bomb near. Good job we moved.

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