Primitive technology begins to look like magic to a sufficiently advanced society.

The hand drill is not suited to the jungle environment.  That’s not to say it can’t work, but rather that the ever present humidity is another obstacle to overcome for a technique that is already difficult to master.

Here’s a question for you – when does humidity create more of a problem for the hand drill: on a snowy mountain top on a cold morning? Or in the jungle on a hot afternoon?  (assume that the relative humidity in both places is 90%)…. it’s hard for me to test the two environments at the same time, but I strongly suspect that the jungle is going to be a much less conducive environment for the hand drill.

The reason I say this is that the absolute humidity is higher in the warmer environment.  I experience this every time I go back to the UK as I almost immediately start to suffer from dry skin and chapped lips (even if the relative humidity is the same as it was in Malaysia)….why?  because my body has become acclimatised to high humidity and the low humidity of the UK throws a spanner into the system.

Relative humidity is a measure of how much water vapour the air can hold in suspension at a given temperature: thus 90% relative humidity means that the air contains 90% of the maximum amount of water vapour it can hold before vapour starts to condense.  If the temperature rises the maximum amount of water vapour the air can contain increases, if the temperature drops the opposite applies.  To put it simply, if the relative humidity stays constant, the actual amount of water vapour in the air at 30C is much higher than if the temperature drops to freezing point. At 30C and 90% relative humidity the air contains 27.3 grams of water per cubic metre (the absolute humidity); at 0C and 90% relative humidity a cubic metre of air contains only 4.4 grams of water.

Absolute humidity is a measure of the actual amount of water vapour in the air, relative humidity is a measure of how much vapour is in the air as a percentage of how much vapour the air can contain at that temperature.

Understanding the impact of humidity is important in the jungle as it has a direct impact on the jungle trekker.  In the early morning the jungle is cool and there is often mist floating through the canopy – why? because the cooling of the air through the night has reduced the maximum amount of water vapour the air can contain and the excess vapour has started to condense.  This is the best time for trekking  – if you have a difficult mountain to climb, do it first thing in the morning and you’ll find it much easier.

As the day gets hotter two things happen – firstly the increase in temperature means that the air can contain more water vapour than it could earlier (when it was cooler), so the mist disappears,  and secondly the jungle starts to ‘sweat’: more water vapour is released from the plants and trees and into the air – a process called transpiration.  Often you can see this happening as clouds start to form above the rain forest during the afternoon.

This is the most uncomfortable time to trek in the jungle – not only is it hotter, but our body’s mechanism for cooling itself (sweating) struggles to work in the high humidity… sweating is evaporative cooling and, at high humidity, the rate at which sweat evaporates from the skin slows right down.  This is a double whammy for the body – firstly you’re getting hotter (simply because the temperature is rising) and secondly the body’s system for cooling itself starts to fail.  The result is you get soaked in all this sweat that isn’t evaporating (as your body tries, in vain, to cool you down), you feel very uncomfortable and lethargic, and you start to dehydrate.  I remember hearing of a rain forest tribe somewhere whose bodies have adapted to this high humidity environment to the point that they hardly sweat at all – unfortunately my body has not developed the same adaptive approach and I sweat I like a pig!

As the jungle continues to release water vapour into the sky the clouds can reach saturation point and you get rain – often this happens at around 6 pm.  If it doesn’t rain then, you may well get rain later on in the night as, when the sun goes down  the temperature cools and the maximum amount of water vapour the air can contain drops.

If it doesn’t rain and the clouds remain, the night will be warmer and more humid as the heat from the earth is trapped by the clouds.  If it rains and the sky is clear, the convective heat loss from the forest will be faster and it can get surprisingly cold (usually making you wake at about 3-4am to wrap your blankets tighter).

For friction fire embers the water vapour in the air is obviously a problem.  It is the reason you see people wafting air onto the ember with their hands rather than blowing onto it (as air from your lungs has more water vapour in it).  High absolute humidity means that you have to work much harder to get an ember than you would in a more arid environment.

Getting the hand drill to work requires a fine balance between speed, pressure, drill diameter, wood condition, wood type, spindle length, technique, notch etc and it can be very unforgiving if you get any of these elements wrong.  Add in the need to overcome the moisture problems and it gets harder still.

This is why the bow drill is a better option – because of the mechanical advantage given by the bow, you can apply serious amounts of both speed and pressure to heat up the wood and dust to a temperature that overcomes any barriers presented by both moisture in the air and, to some extent, moisture in the wood.

So all this, I am aware, doesn’t exactly do a good job of selling the hand drill technique to fellow junglecrafters.  Why bother with it at all?  Is it nothing more than a party trick and of no real practical use in the jungle?

My view, unsurprisingly, is that it is very much worth learning.  The sense of satisfaction you get with your first ember from the hand drill is far greater than with other friction fire methods (at least it was for me).  The associated skills (carving, joining drill tips to spindles, knots, tree identification, wood condition knowledge) are also applicable to other aspects of junglecraft as well.

As for the question of practicality I would say this – if I were stuck in the jungle for an extended period I would definitely make up a hand drill set from ideal materials (i.e. combinations that I know would produce embers easily, but these would usually require a couple of days to dry out) and it can also be done on-the-spot with dead wood found in the forest (but these tend to be harder to get embers from).

But, you may ask, what is the point of learning any of these primitive technology skills?  For me, it is because you get a true feeling of self sufficiency and because they’ll never develop an ‘app’ that can light a fire for you…