92 Spital,
Aberdeen,
May 1854
My Dear Uncle
I am sorry that I don’t manage to explain the balloon correctly, but I hope
to explain better this time. The Hydrogen being much heavier (1) than common
air ascends in the atmosphere till it reaches a place where the air and it are of
the same rarity in like manner when a quantity of Hydrogen is enclosed in a silk
bag or any other light material it ascends, being much lighter than common air,
until it reaches a place where it displaces a quantity of air equal to its own
weight and that of the silk &c and there it will remain, things remaining as
they were – this is not much better than former explanations.
(1) [marginal note in a different handwriting] it is the lightest of all gases,
but I suppose this was a lapsus pennae [Latin for ‘slip of the pen’],
as you subsequently assign the real cause of the ascension of a balloon
I intended to inform you better regarding the class I left, but had not
sufficient room, before I was in the highest mathematics class, but now
another class has commenced, for the students, such as Mr Cochrane and
those who were at the Gymnasium before, i.e. those who were at College the
last session, and require mathematics for the second year, this is the class
that I joined, and we are now at the 6th book.
The Homer that I have got is Ferguson’s edition, which only contains
four books. It has a vocabulary which helps a good deal. Homer uses rather
strange cases compared to Xenophon, and I find it somewhat difficult. I have
been at the bookseller’s today – he had not the book you mentioned, but
he is to get it for me by next week.
I am able to make out all your remarks, and that is the first thing I look
to when I get a letter from you.
I remain
Yours Affectionately James Campbell
You should get Fowne’s Manual of Chemistry just published at 12/- a new
Edition edited by Jones and some other person whose name I forget.
|
