In the past few days I have been strolling through my notes, which I
have made in 1975.
I have found out that a lot of (student) observers have been involved
in the project.
During the period I was at La Palma there where at least 6 other
persons active in some way or another. I should have addresses of some
of them, but I did not find those addresses yet.
First will try to give description of the things we did on the site:
Every hour (on the hour) during the night readings were made of the
direction and the strength of the wind, of the humidity and of the
temperature. In the cabin on top near the telescope (which you will
see on the photographs / slides which you will receive later) there
where recorders placed, which kept a constant track of the barometer
readings and of the humidity en temperature readings on a second
Besides that every hour a photographic trail was made of the polar
star and every other night (?) photometric readings where made of 6
high (near the zenith) and 6 low (near the horizon) stars both with
and without a redfilter.
I am not sure, but the copies of the reports we have seen in the
archive on site suggest, that premilary site testing had taken place
and that definitive testing starting somewhere in 1975 at the same
time that that decision had been taken to close the Iza¤a site on
I arrived at the site on September 28, 1975 together with Donald
Kennedy. He came from Edinborough in Scotland and was a student over
there. Although I told you we had to walk up from Puntagorda, I found
out that we came up from Juan Ianes, which is more close to Los Llanes
according to a map of La Palma of those days (I don't recollect to
have seen this place while I was on La Palma a few weeks ago!). It is
located on a road into the mountains which leaves the main road
roughly half way between El Time and Puntagorda.
We did not go up path along the Caldera and the path arrived at the
cabin coming from the place where the administration buildings are now
The fuente I told you about must have been a lot further away as I
thought, because my notes say that it took 1 hour to get there, to
fetch water and to return. I was certainly not at fuenta nueva,
because I am 100% positive we did not pass the telescope, but went in
the direction I pointed to you.
There were 3 cabins on the site. One was located next to the brick
wall (this was the one we slept and lived in), one was about 50-100
meters roughly at the same height in the direction of the telescope.
This was used to store things. The third one was on top near the
telescope and contained the recorders and was used to store the
telescope in bad weather conditions (fog, clouds). With the photograps
/ slides you might by able to spot the places, where they stood.
There were two masts with a length of 12 meters on which the sensors
for temperature readings were placed.
From here on I will try to give my notes in a chronological order:
I had to come to La Palma quite suddenly. I was supposed to change
places with a colleague
student from the University of Amsterdam (Peter Bouwman) he returned
home after one night, because he was scared to death by the goats
roaming around freely during the night. He quit Astronomy right after
On September 30, 1975 the Iza¤a site on Tenerife was closed down and
this was the last day we had contact by walkie talkie with Tenerife(!)
. On October 1, 1975 the telescope which was used over there was
brought in to Santa Cruz by ship as well as the Landrover which had
been used on Tenerife. With this Derryck Andrews (from Scotland)
arrived in Los Llanos. He was the last person on the Tenerife site.
On October 1, 1975 we made precautions to prevent the cables being
bitten through by the wild goats (probably the ancestors of the ones
we saw 2 weeks ago!), which were roaming the place at that time (also
Because one mast with temperature sensors was located on a spot which
was very windy it was brought down on October 3.
October was a very windy month on top as you may see further on. On
October 3 the wind reached up to 66 miles per hour.
On October 4 the masts was re-erected on an other place and built up
to a height of 11, 5 meters.
On October 6 Paul Cass and Neil Andersen came up to the site and
Donald returned with Paul to Los Llanos.
Paul was a technician from the University of London and was (to my
knowledge) in charge of the La Palma operation. Neil was a colleague
of Donald from Edinborough. That night the biggest forest fire in more
than 100 years started in the east of the Island.
On October 7 we were enclosed on all sides by the fire, but luckely
enough it did not reach us.
On October 8 we still could not do any observations on the polar star,
also because the wind was gusting up to 64 miles per hour.
On October 9 the maximum wind was down a maximum of 58 miles per hour.
On October 10 we could restart our observations, but had to bring in
the telescope at 5 o'clock in the morning because of have clouds
covering the sites. It was stored in the topcabin.
During day time or while not in use the telescope (which had a 10 cm
aperture) was covered with lenshoods.
Normally supplies were brought in every 2 or 3 days, but this had been
impossible because of the forest fire. During those days we were in
contact via walkie talkie 2 times a day. The Los Llanos people drove
up the the lookout point in the Caldera de Taburiente to get in touch.
On October 11 Derryck came up with parts of the Iza¤a telescope and
Neil went back to Los Llanos.
On October 13 new supplies were brought in together with other parts
of the telescope.
On October 14 the rest of the telescope was brought in (all with
That same day we started to flatten a part of the site for the
erection of the second telescope (so the observations were made with 2
telescopes!). I do not recollect were this place was, but I am sure it
was quite near the other telescope.
On October 15 Luis _.. (an observer from the mainland of Spain) came
up and I went down to Los Llanos.
On October 18 Paul and Donald went up and on October 21 Luis came down
and Donald went up. That night the wind reached a maximum of 83 mph
(133 km per hour).
Paul nearly always returned the same day because he did not make any
In Los Llanos we were living in a (part of a) house which was rented
from the Olsen family and as far as I could see from my slides it was
located in the direction of El Paso, on the mountain side with some
platanos plantage in front of it.
On October 23 the Olsen family (he was American, she English) made a
tape recording of our where abouts due to the forest fire while we
were located on top. Maybe it is possible to trace this family and ask
for this tape.
On October 24 I returned to Gran Canaria to go home. Another student
from Amsterdam (Theo van der Linden) came over on the same day to take
I have no notes of copies of the observations we made at the site. So
I can not help you with that. I will now first have some photographs
made from my slides and try to compile a plan of the site from that. I
will send these to you and after that there will by made copies of my
slides and send them after they are finished.
If you have any specific questions please let me know.
In the meantime I wish you all the best for 1998.