fix a link in survey/how and provide some other notes on scale drawing.

also begin splitting up hints into stuff more or less relevant to modern
instruments.

handbook/survey/hints.htm

@@ -8,37 +8,18 @@
 <h2 id="tophead">CUCC Expo Surveying Handbook</h2>
 <h1>Wookey's hints and tips</h1>
 
-<p>... to save you going back to do it again.
+<p>... to save you going back to do it again.</p>
 
 <p><i>"hmm - not going to finish this even slightly, so some points to bear
 in mind:"</i></p>
 
 <ul>
-<li>The compass must be held level to get a meaningful reading. A left/right
-tilt will cause a systematic over or under reading, whilst sighting up or
-down a steep leg may cause the compass to stick. It is easier to sight from
-the lower station by keeping the tape in position and sighting along it.</li>
-
 <li>Take care with lights, batteries, helmets and anything else which could
 be magnetic - check your gear on the surface, or your work could be seriously
 impaired. If your light affects the compass, then hold it away from the
 instrument when lighting it. Keep the compass well away from steel objects
 like bolts, steel karabiners or maillons, tripods or ammo cans when sighting.</li>
 
-<li>Practice using the compass above ground to avoid classic errors like
-reading 56 as 64 (ie. counting the wrong way from the 60 marker).</li>
-
-<li>Degrees are on the <b>left hand</b> scale on clinos. The other scale is
-percent gradient - this is better than nothing if you can't read the degree
-scale (make it abundantly clear in the notes), but reading the wrong one
-without realising gives useless results.</li>
-
-<li>Pick survey points so you can get your head in, and so you can see both
-ways as easily as possible. Note that Bolts are good things to use as
-stations (because we can find them again), but don't put the compass within
-30cm as it will give joke readings. Sight from the other end of the leg, or
-put the compass behind it and look <em>past</em> the bolt.</li>
-
 <li>Write decimal points as slashes to stop them getting lost in the mud.
 Make sure they don't look like "1"s. It is helpful to always write compass
 readings as three digits before the decimal point, and clino as two digits
@@ -59,16 +40,6 @@ might get rubbed off.</li>
 
 <li>Take at least one spare pencil!</li>
 
-<li>Return instuments to the dessicator before you fall asleep
-otherwise they are likely to fog up the next time. Don't leave them in the
-cave, both for the above reason and because the next survey may need them
-somewhere else entirely.</li>
-
-<li>Leapfrogging is a good idea in general but you don't have to be religious
-about it. It is almost impossible in tiny passage, and sometimes a point for
-a survey station is so obvious that you <em>have</em> to use it, but can't
-actually take readings <i>from</i> it.</li>
-
 <li>Draw plans and extended elevations in horizontal bits of cave, with
 cross sections for each typical section of passage. Orientate your cross
 sections (ie. show which direction they are looking) on the plans. It helps
@@ -80,10 +51,6 @@ impossible to orientate later. A plan with only one station and no direction
 indicator cannot be orientated. It is easiest if the drawer takes a spare
 compass for this (doesn't have to be a good one) in vertical work.</li>
 
-<li>Think ahead when surveying pitches, especially long ones. Take two tape
-measures for stuff over 30m, or three well-organised people and some handy
-big croc-clips!</li>
-
 <li>Record the serial numbers of instruments (comp/clino/tape). Also write
 down dates, endpoints, surveyors, cave, any conventions used for symbols,
 passage widths etc.</li>
@@ -93,6 +60,43 @@ otherwise your surveys will be left hanging in space. From 1996, the QM
 list is supposed to tell you the nearest existing survey station - make
 sure that you can identify this (look at the relevant year's survey book).</li>
 
+</ul>
+
+<h3>If using analogue instruments (i.e. Suunto)</h3>
+<ul>
+<li>The compass must be held level to get a meaningful reading. A left/right
+tilt will cause a systematic over or under reading, whilst sighting up or
+down a steep leg may cause the compass to stick. It is easier to sight from
+the lower station by keeping the tape in position and sighting along it.</li>
+
+<li>Practice using the compass above ground to avoid classic errors like
+reading 56 as 64 (ie. counting the wrong way from the 60 marker).</li>
+
+<li>Degrees are on the <b>left hand</b> scale on clinos. The other scale is
+percent gradient - this is better than nothing if you can't read the degree
+scale (make it abundantly clear in the notes), but reading the wrong one
+without realising gives useless results.</li>
+
+<li>Pick survey points so you can get your head in, and so you can see both
+ways as easily as possible. Note that Bolts are good things to use as
+stations (because we can find them again), but don't put the compass within
+30cm as it will give joke readings. Sight from the other end of the leg, or
+put the compass behind it and look <em>past</em> the bolt.</li>
+
+<li>Return instuments to the dessicator before you fall asleep
+otherwise they are likely to fog up the next time. Don't leave them in the
+cave, both for the above reason and because the next survey may need them
+somewhere else entirely.</li>
+
+<li>Leapfrogging is a good idea in general but you don't have to be religious
+about it. It is almost impossible in tiny passage, and sometimes a point for
+a survey station is so obvious that you <em>have</em> to use it, but can't
+actually take readings <i>from</i> it.</li>
+
+<li>Think ahead when surveying pitches, especially long ones. Take two tape
+measures for stuff over 30m, or three well-organised people and some handy
+big croc-clips!</li>
+
 <li>Calibration is useful at 161a: ie. compass from lower to upper cairn, and
 from lower cairn to Br&auml;uning Zinken (if you know where it is - highest
 point near right-hand edge of Br&auml;uning Wall (just over the bush!)). See

handbook/survey/how.htm

@@ -26,6 +26,7 @@ chance to survey, on the derigging trip of a cave which is now "finished"),
 it is better to record all the passage, rather than part of it to a very high
 standard. Particularly to be avoided is a survey that doesn't connect to the
 rest of the cave.</p>
+
 <p><img class="onleft" width=70% src ="../i/76-clipart.png" />
 You are collecting data to fulfill a number of needs: the actual position
 of the passage for finding where it goes and possible connections; the shape
@@ -81,9 +82,19 @@ visible, to record the location of shelly bands, faults, dip and strike of
 any prominent bedding or other cleavage planes, and any old flow markings
 (direction and approx diameter). Anything unusual which would make a good
 landmark is also useful, and of course, man-made things like pitch rigging,
-traverse lines or cairns.</li>
+traverse lines or cairns. Refer to the
+<a href=https://www.carto.net/neumann/caving/cave-symbols/uis_signatures_english.pdf>
+UIS standard symbols</a> for a general guide.</li>
 
-<li>We use Therion protractors undergound for estimating directions when we are sketching passage shape and direction. We have templates in <a href="../templates/therion1_250.pdf">1:250</a> and <a href="../../templates/therion1_500.pdf">1:500</a> scales. (Thanks to Martin Budaj for these.)
+<li>We use Therion protractors undergound for estimating directions when we are
+sketching passage shape and direction. We have templates in
+<a href="../../templates/therion1_250.pdf">1:250</a> and
+<a href="../../templates/therion1_500.pdf">1:500</a> scales. (Thanks to Martin
+Budaj for these.). Some alternatives for those without access to transparency
+slides include an orienteering compass with scale (e.g.
+<a href=https://silvasweden.com/collections/compasses/products/compass-classic>
+a silva compass</a>), or a metric
+<a href="http://cavecompass.com/">cave compass</a></li>
 
 <li>The left, right, up, down (LRUD) from the survey station to the general
 passage wall, not the closest piece of rock. These should be <b>measured</b>