A similar principle can be used on land to find towns or villages. The number of roads, paths, power lines and communication cables increases as you get nearer a town; of course light and noise pollution also increase. There are some more ‘lateral’ clues too.

On the weekend I was walking with friends in the South Downs. My friend had the map and so I did not know exactly how far we were from our lunch stop, the George and Dragon pub in the West Sussex village of Burpham. We had been walking for about 9 miles, in deep snow and along slushy paths. We were hungry, which can help sharpen the senses.

I knew that we were within half a mile of the village when the incidences of dog mess sky-rocketed along the sides of our path. Dog-walkers are habitual and have their rituals. The path we were following into the village was clearly a favourite short walk for the dog-owning villagers. There were at least one hundred poops in the space of four hundred metres. Disgusting, yes, but in a strange way a welcome navigational sight. Lunch could not be more than 15 minutes away!

In the book I emphasise the importance of using our senses in natural navigation. I cover examples from the sound of birdsong to the smell of trampled fruit in London.

I stumbled across a kindred spirit on the Internet this morning in Sachin Somanna, the author of this article about Gayathri Tiffin Room. It certainly smells from here like one of the joys of the Indian city of Mysore:

“We do not need any directions to reach Gayathri Tiffin Room (or GTR as it is popularly known) because once we close in on Chamundipuram circle, the irresistible aroma of a Mysore Masala Dosa works like a natural navigator to this vegetarian restaurant that is located just a few meters from the circle.  Although the restaurant looks rather plain on the outside, the packed crowd inside negates this observation. GTR is filled with foodies digging into some varying and rather tempting South-Indian cuisine.”

Early yesterday morning I was struck by the strong smell of smoke outside. It was not the smell of fresh fire, more the heavy scent of a diffuse smoke in a damp air, so I was not concerned. My initial thought was that a southerly breeze must be carrying the smoke from the nearest village up our way, but then there did not appear to be any breeze at all. The air was distinctly stagnant. The smell was not varying at all in the way that smoke carried on the wind does,  growing weaker and stronger each second.

When I looked down into a valley the cause became clear. There was a temperature inversion, where warmer air sits on top of cooler air trapping it and everything in it close to the ground. The inversion layer can just be made out in this photo.

If navigation is about where we are and where we are going, then the senses have a bigger part to play than many realise, and not just physically. Marion’s passage about a passage beautifully illustrates that honing our senses can get us to our destination in more ways than one. She found land and a new career.

Here are some excerpts:

‘Wall-to-wall ocean, especially in the warm tropics, does something to your senses…

…salt crystals form on the decks and railings–even your skin– like granules of sugar. With the acrid smell of ocean water and sweat, always sweat, mixed with suntan lotion and more salt air, your nose is dulled with monotony…

Leaning against the metal railing like race horses at the starting gate, we peered at the horizon, straining to see land.

I smelled it hours before I saw it. Green. Chlorophyll. Leaves. Land. The round smell was sweet and full.

The smell of land triggered more than tears of joy. It told me that it was time to take a new road in life; to find a new job. Within a year I’d moved to Kodiak Island and followed a compelling urge to learn everything I could about gardening.’