I think that most of the concerns raised in this thread regarding the
Palantíri are actually addressed in the essay on the Palantíri in
/Unfinished Tales/. For obvious reasons I won't reproduce the entire
essay, but I will try to include enough to provide some answers.
III THE PALANTÍRI
The palantíri were no doubt never matters of common use
or common knowledge, even in Númenor. In Middle-earth they
were kept in guarded rooms, high in strong towers, only
kings and rulers, and their appointed wardens, had access
to them, [...]. But until the passing of the Kings they
were not sinister secrets. [...]. [1]
After the days of the Kings, and the loss of Minas Ithil,
there is no further mention of their open and official use.
There was no answering Stone left in the North after the
shipwreck of Arvedui Last-king in the year 1975.[2] In 2002
the Ithil-stone was lost. There then remained only the
Anor-stone in Minas Tirith and the Orthanc-stone.[3]
Two things contributed then to the neglect of the Stones,
and their passing out of the general memory of the people.
The first was ignorance of what had happened to the Ithil-
stone: [...]; but it was clearly possible that it bad been
seized and had come into the possession of Sauron, and some
of the wiser and more farseeing may have considered this.
It would appear that they did so, and realized that the
Stone would be of little use to him for the damage of
Gondor, unless it made contact with another Stone that was
in accord with it.[5] It was for this reason, it may be
supposed, that the Anor-stone, about which all the records
of the Stewards are silent until the War of the Ring, was
kept as a closely-guarded secret, accessible only to the
Ruling Stewards and never by them used (it seems) until
Denethor II.
The second reason was the decay of Gondor, and the waning
of interest in or knowledge of ancient history among all
but a few even of the high men of the realm, [...].
Communications depended on messengers and errand-riders, or
in times of urgency upon beacons, and if the Stones of Anor
and Orthanc were still guarded as treasures out of the
past, known to exist only by a few, the Seven Stones of old
were by the people generally forgotten, and the rhymes of
lore that spoke of them were if remembered no longer
understood; [...].
The Orthanc-stone appears to have been at this time long
disregarded by the Stewards: it was no longer of any use to
them, and was secure in its impregnable tower. [...].
Isengard remained a personal possession of the Stewards,
but Orthanc itself became deserted, and eventually it was
closed and its keys removed to Minas Tirith. If Beren the
Steward considered the Stone at all when he gave these to
Saruman, he probably thought that it could be in no safer
hands than those of the head of the Council opposed to
Sauron.
Saruman had no doubt from his investigations[6] gained a
special knowledge of the Stones, things that would attract
his attention, and had become convinced that the Orthanc-
stone was still intact in its tower. [...]. At that time
the matter of the Orthanc-stone would hardly concern the
White Council. Only Saruman, having gained the favour of
the Stewards, had yet made sufficient study of the records
of Gondor to perceive the interest of the palantíri and
the possible uses of those that survived; but of this he
said nothing to his colleagues. [...]. 7
The Council in general must independently have known of
the Stones and their ancient dispositions, but they did not
regard them as of much present importance: they were things
that belonged to the history of the Kingdoms of the
Dúnedain, marvellous and admirable, but mostly now lost or
rendered of little use. [...].
Though (warned by Gandalf) the Council may have begun to
doubt Saruman's designs as regarded the Rings, not even
Gandalf knew that he had become an ally, or servant, of
Sauron. This Gandalf only discovered in July 3018. But,
although Gandalf had in latter years enlarged his own and
the Council's knowledge of Gondor's history by study of its
documents, his and their chief concern was still with the
Ring: the possibilities latent in the Stones were not
realized. It is evident that at the time of the War of the
Ring the Council had not long become aware of the doubt
concerning the fate of the Ithil-stone, and failed
(understandably even in such persons as Elrond, Galadriel,
and Gandalf, under the weight of their cares) to appreciate
its significance, to consider what might be the result if
Sauron became possessed of one of the Stones, and anyone
else should then make use of another. It needed the
demonstration on Dol Baran of the effects of the Orthanc-
stone on Peregrin to reveal suddenly that the 'link'
between Isengard and Barad-dûr (seen to exist after it was
discovered that forces of Isengard had been joined with
others directed by Sauron in the attack on the Fellowship
at Parth Galen) was in fact the Orthanc-stone - and one
other palantír.
In his talk to Peregrin as they rode on Shadowfax from
Dol Baran (The Two Towers III 11) Gandalf's immediate
object was to give the Hobbit some idea of the history of
the palantíri, [...]. He was not concerned to exhibit his
own processes of discovery and deduction, except in its
last point: to explain how Sauron came to have control of
them, so that they were perilous for anyone, however
exalted, to use. But Gandalf's mind was at the same time
earnestly busy with the Stones, considering the bearings of
the revelation at Dol Baran upon many things that he had
observed and pondered: such as the wide knowledge of events
far away possessed by Denethor, and his appearance of
premature old age, first observable when he was not much
above sixty years old, although he belonged to a race and
family that still normally had longer lives than other men.
[...]. Gandalf's dealings with Denethor on arrival in Minas
Tirith, and in the following days, and all things that they
are reported to have said to one another, must be viewed in
the light of this doubt in Gandalf's mind.[8]
The importance of the palantir of Minas Tirith in his
thoughts thus dated only from Peregrin's experience on Dol
Baran. But his knowledge or guesses concerning its existence
were, of course, much earlier. [...].
But the Anor-stone had become a secret: no mention of its
fate after the fall of Minas Ithil appeared in any of the
annals or records of the Stewards. [...]. Gandalf should
have been reported as saying that he did not think that
Denethor had presumed to use it, until his wisdom failed.
He could not state it as a known fact, for when and why
Denethor had dared to use the Stone was and remains a
matter of conjecture. [...].
[...].
In the case of Denethor, the Steward was strengthened,
even against Sauron himself, by the fact the Stones were
far more amenable to legitimate users: most of all to true
'Heirs of Elendil' (as Aragorn), but also to one with
inherited authority (as Denethor), as compared to Saruman,
or Sauron. It may be noted that the effects were different.
Saruman fell under the domination of Sauron and desired his
victory, or no longer opposed it. Denethor remained
steadfast in his rejection Sauron, but was made to believe
that his victory was inevitable, and so fell into despair.
[...].
NOTES
[1] Doubtless they were used in the consultations between
Arnor and Gondor in the year 1944 concerning the succession
to the Crown. The "messages" received in Gondor in 1973,
telling of the dire straits of the Northern Kingdom, was
possibly their last use until the approach of the War of
the Ring. [Author's note.]
[2] With Arvedui were lost the Stones of Annúminas and Amon
Sûl (Weathertop). The third palantír of the North was that
in the tower Elostirion on Emyn Beraid, which had special
properties (see note 16).
[3] The Stone of Osgiliath had been lost in the waters of
Anduin in 1437, during the civil war of the Kin-strife.
[...]
[5] By themselves the Stones could only see: scenes or figures
in distant places, or in the past. These were without
explanation; and at any rate for men of later days it was
difficult to direct what visions should be revealed by the
will or desire of a surveyor. But when another mind
occupied a Stone in accord, thought could be 'transferred'
(received as 'speech'), and visions of the things in the
mind of the surveyor of one Stone could be seen by the
other surveyor. [...] [Author's note.]
[6] Cf. Gandalf's remarks to the Council of Elrond concerning
Saruman's long study of the scrolls and books of Minas
Tirith.
[...]
[8] Denethor was evidently aware of Gandalf's guesses and
suspicions, and at once both angered and sardonically
amused by them. Note his words to Gandalf at their meeting
in Minas Tirith (The Return of the King V 1): [...].
In message <news:slrng8pm2h.hbb.er_pease@hedge06.Stanford.EDU>
Emma Pease <er_pease.RemoveThis@yahoo.com> spoke these staves:
>
> On 2008-07-27, Öjevind Lång <bredband.net.RemoveThis@ojevind.lang> wrote:
>>
>> But it came as a surprise to Gandalf that Saruman had a palantír.
>> Gandalf had been to Gondor more than once, and I can't think of
>> any reason why the circumstance that Saruman had been entrusted
>> with a palantír would have been withheld from him.
I think the above addresses the reasons why the White Council had
been unaware of this. Whether we agree with Tolkien's assessment that
this oversight was understandable 'even in such persons as Elrond,
Galadriel, and Gandalf, under the weight of their cares' is, of
course, a different matter, though I'd be the last to blame others
for overlooking even important matters that aren't staring in your
eyes when one is busy with other matters (I've been down that road
too many times myself to blame others of it <GG>).
> I suspect the palantiri had been forgotten about except by people
> who were actively looking for objects (such as Saruman) or who
> were responsible for them (such as Denethor).
Precisely. I cut out a passage describing how the information gained
from the palantíri were, in later times, ascribed to some mystical
elvish powers of the Kings (these powers doubtlessly ascribed to
their being of Lúthien's line) just as the thing about their healing
hands. Apparently there was a good deal of mythologizing about the
Kings in Gondor during the reign of the Stewards.
> Gandalf's area of study had not been Gondor or objects.
Except, of course, as it pertained to Arnor or, in the period after
'The Hobbit', to the One Ring.
> Knowing where the stones were was something he might never had
> learned or thought important
And knowing where the stones had been kept a thousand years earlier
is not the same as knowing where they were now -- in particular as
some of the stones were well known to have been lost; a fate that
could reasonably be assumed to have befallen also the other stones
about which nothing was known.
> After Saruman's treason had become apparent, Gandalf never
> visited Minas Tirith,
Depending, of course, on how 'apparent' you mean

As the above
text explains, Gandalf did, in the last half-century or so before the
War of the Ring, go to Minas Tirith some two or three times and he
became the primary source of knowledge about that realm for the White
Council.
--
Troels Forchhammer
Valid e-mail is <troelsfo(a)gmail.com>
Please put [AFT], [RABT] or 'Tolkien' in subject.
Everything should be made as simple as possible, but not
simpler.
- Albert Einstein
>> Stay informed about: What was Sauron thinking?