70 years ago: Hong Kong's wartime diaries

The idea of these new boilers is to have three cylinders, each holding 25 gallons (they are the hot water cylinders installed in all these flats, which we propose to dismantle) set in a row. The fire will burn under the first of the series (the one furthest from the flue) and the flue gases, after passing out of the first boiler, will first circulate round the second boiler, and then around the third boiler before finally entering the flue proper. This will utilize, as far as possible, the greater percentage of the heat generated instead of wasting about half of it, as is the case with most solid fuel boilers. It will ensure a constant supply of hot water for replenishing the first boiler: it is just possible that the water in the second boiler may be brought to boiling point, especially if it is only half filled; but in any case, I think I will build a second fireplace under the second boiler, complete with fire and ash pit doors so that it can be lit for a few minutes to bring the water actually to the boil during the rush periods and then shut off completely so that all draught comes from the first boiler. It will be interesting to see if this scheme works, for the waste gases from the first fire may prevent the second one from burning. We intend to burn, in these water boilers, principally dried grass. We have a squad of grass-cutters who cut the long grass from the hillsides and spread it out to dry.

I intend to get one or two of the less fit men to twist it into small hanks and knot it so that it will be easier to handle and does not burn away too quickly. It will be necessary to use a little wood too, but we hope to keep this down to a very small amount. In the kitchen, after this job is finished, I intend to rebuild one of the stoves (the one I built myself about a year ago) inserting a cylinder and bringing the flue gases from the two other boilers around it before entering the flue so that the cooks in the galley will have a constant supply of hot water – without burning extra fuel – with which to top up rice and stew boilers instead of having to do it, as at present, with cold. This too should conserve fuel consumption.

The wood situation in the Colony is becoming increasingly difficult. It will be awful to go back and find the Colony practically denuded of trees. So long as the Japanese still believe they are going to keep the place, they will probably be careful of such amenities, but when they find they have probably got to go, I don’t suppose they will mind what happens to the place.