A Treatise on the True Devotion to the Blessed Virgin by St. Louis-Marie Montfort(faithful translation of Fr. Faber, of which he says he says: "I have translated the whole treatise myself, and have taken great pains with it, and have been scrupulously faithful." The TAN books edition has the same words "scrupulously faithful", making the book look like the faithful translation of Fr. Faber, but in fact, is a different translation. They did more than just update the archaic words and expressions in the new translation. Some parts are more clearer in the original translation than in the new translation, and vice versa; one should read both translations, as well as another translation which is another variant of the newer translation, available here: http://www.montfort.org.uk/Writings/TrueDev.html)

This is a very important book; Fr. Faber says in preface: "...GOD is pressing for a greater, a wider, a stronger, quite another devotion to His Blessed Mother. I cannot think of a higher work or a broader vocation for any one than the simple spreading of this peculiar devotion...Let a man but try it for himself, and his surprise at the graces it brings with it, and the transformations it causes in his soul, will soon convince him of its otherwise almost incredible efficacy as a means for the salvation of men...." http://books.google.com/books?vid=03hNpWi9X7ZBRisb&id=OccCAAAAQAAJ&pg=RA1-PR17&lpg=RA1-PR17&dq=montfort&as_brr=1

Preface of Fr. Faber
…
All those who are likely to read this book
love God, and lament that they do not love Him
more; all desire something for His glory,—the
spread of some good work, the success of some
devotion, the coming of some good time. One
man has been striving for years to overcome a
particular fault, and has not succeeded. Another
mourns, and almost wonders while he
mourns, that so few of his relations and friends
have been converted to the faith. One grieves
that he has not devotion enough; another that
he has a cross to carry, which is a peculiarly
impossible cross to him; while a third has domestic
troubles and family unhappinesses, which
feel almost incompatible with his salvation; and
for all these things prayer appears to bring so
little remedy.
But what is the remedy that is
wanted? what is the remedy indicated by God
Himself? If we may rely on the disclosures of
the Saints, it is an immense increase of devotion
to our Blessed Lady; but, remember, nothing
short of an immense one.
Here, in England,
Mary is not half enough preached. Devotion
to her is low and thin and poor.
...
Hence
it is that Jesus is not loved, that heretics are
not converted, that the Church is not exalted;
that souls, which might be saints, wither and
dwindle; that the Sacraments are not rightly
frequented, or souls enthusiastically evangelised.

Jesus is obscured because Mary is kept in the
background. Thousands of souls perish because
Mary is withheld from them. It is the miserable
unworthy shadow which we call our devotion
to the Blessed Virgin that is the cause of all
these wants and blights, these evils and omissions
and declines. Yet, if we are to believe
the revelations of the Saints, God is pressing for
a greater, a wider, a stronger, quite another
devotion to His Blessed Mother.
I cannot think
of a higher work or a broader vocation for any
one than the simple spreading of this peculiar
devotion of the Venerable Grignon de Montfort.
Let a man but try it for himself, and his surprise
at the graces it brings with it, and the
transformations it causes in his soul, will soon
convince him of its otherwise almost incredible
efficacy as a means for the salvation of men,
and for the coming of the kingdom of Christ.

Oh, if Mary were but known, there would be no
coldness to Jesus then ! Oh, if Mary were but
known, how much more wonderful would be our
faith, and how different would our Communions
be! Oh, if Mary were but known, how much
happier, how much holier, how much less worldly
should we be, and how much more should we
be living images of our sole Lord and Saviour,
her dearest and most blessed Son!

I have translated the whole treatise myself,
and have taken great pains with it, and have
been scrupulously faithful.
[note: the TAN books version uses this same preface of Fr. Faber but does not use his translation of the book and did more than just update the few archaic languages.]
At the same time,
I would venture to warn the reader that one
perusal will be very far from making him master
of it. If I may dare to say so, there is a growing
feeling of something inspired and supernatural
about it, as we go on studying it; and
with that we cannot help experiencing, after
repeated readings of it, that its novelty never
seems to wear off, nor its fulness to be diminished,
nor the fresh fragrance and sensible fire
of its unction ever to abate.

F. W.
FABER,
...
1862.