diff --git a/README.md b/README.md
index a8f8bf4..62720af 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,21 @@ Functions to compute relative humidity, absolute humidity, wet bulb
 temperature, and other values related to humidity of air, given 
 partial data.
 
+## Purpose
+
+I'm using this code to explore human survivability given global warming. The following essays of mine are relevant:
+
+1. [The Everyone Dies Event Class](https://www.journeyman.cc/blog/posts-output/2021-11-15-the-everyone-dies-event-class/)
+2. [The 'everyone dies' event comes home](https://www.journeyman.cc/blog/posts-output/2026-07-15-Everyone-dies-UK/)
+3. [Extreme Heat](https://www.journeyman.cc/blog/posts-output/2026-07-31-Extreme-Heat/)
+4. [Analysis of 2026 heatwaves UK](https://www.journeyman.cc/blog/posts-output/2026-08-04-Analysis-of-2026-heatwaves-UK/)
+
+
+## Status
+
+
+Alpha-quality code. It more or less works but it isn't at all polished.
+
 ## General architecture
 
 ### The packet
@@ -13,12 +28,12 @@ for some of the following keywords:
 
 1. `:absolute-humidity`
 2. `:actual-vapour-pressure` *not yet implemented*
-1. `:dew-point`
+1. `:dew-point` *not yet implemented*
 2. `:pressure-pascals` 
 3. `:pressure-millibars` 
-4. `:saturation--vapour-pressure`
+4. `:saturation-vapour-pressure`
 5. `:relative-humidity`
-6. `:temperature`
+6. `:temperature` *assumed to be celsius*
 7. `:temperature-celsius` 
 8. `:temperature-kelvin` 
 
@@ -26,14 +41,48 @@ These keywords represent variables in the pressure equations, and they are all
 to a degree inter-related; so if you have (or can assume) some of them, you can
 compute others.
 
-Rather than having a mess of functions all of which call one another, which 
-seemed likely to result in horrible messes and potential infinite recursion,
-there is one central function, `humidity.core/resolution`, which takes a 
-partial package and repeatedly tries to compute the values for more variables
-until it can compute no more, and then returns the enhanced packet.
+Rather than having a tangle of functions all of which call one another, which seemed likely to result in horrible messes and potential infinite recursion, there is one central function, `humidity.core/resolution`, which takes a partial packet and repeatedly tries to compute the values for more variables until it can compute no more, and then returns the enhanced packet.
+
+Thus:
+
+```clojure
+humidity.core=> (use 'humidity.core :reload)
+nil
+humidity.core=> (resolution :relative-humidity 100 :temperature-celsius 35)
+{:relative-humidity 100, :temperature-celsius 35, :pressure-pascals 101325, :pressure-millibars 4053/4, :saturation-vapour-pressure 5622.488734516426, :temperature-kelvin 308.15, :absolute-humidity 3953.618101887827}
+```
 
 At present there are no checks to ensure that the packet makes sense.
 
-Associated with each variable there is a namespace which takes a packet, and,
-if that packet contains enough information to compute that variable, returns
-a numeric value, else `nil`.
+Associated with each variable there is a namespace which contains a function that takes a packet, and, provided that packet contains enough information to compute that variable, returns a numeric value, else `nil`.
+
+## Developing
+
+This is a fairly standard [leiningen](https://leiningen.org/) project. I  anticipate that most Clojure developers will have leininen installed, even if they no longer use it much. Start a repl with
+
+```
+lein repl
+```
+
+and hook in your preferred editor as appropriate for that editor.
+
+## Testing
+
+Tests are reasonably complets but all could do with more examples, especially around the crucial 35° C wet bulb area and towards the extremities of  normal weather range. If you are contributing additional code, I would appreciate it being accompanied by tests.
+
+I suggest running tests using
+
+```
+lein cloverage
+```
+
+As this gives not only pass/fail output, but also test coverage output.
+
+## Contributing
+
+Pull requests are welcomed, provided they do not contain AI generated code. I'm not going to waste time debugging Claude's mess, my own is bad enough.
+
+## License
+
+Copyright © 2026 Simon Brooke. Licensed under the GNU General Public License,
+version 2.0 or (at your option) any later version.
diff --git a/test/humidity/wet_bulb_test.clj b/test/humidity/wet_bulb_test.clj
index 21cec52..267ba44 100644
--- a/test/humidity/wet_bulb_test.clj
+++ b/test/humidity/wet_bulb_test.clj
@@ -49,7 +49,6 @@
       (println (format "Expected: %s...%s; actual: %s" min-expected max-expected actual))
       (is (< min-expected actual max-expected)))
 
-
     (let [min-expected 31
           max-expected 34
           temperature 40