2012 December 3
A Miscellany of Extracts from
Notes to Assist the Memory in Various Sciences
by
Walter Hamilton (best known as an
expert on India)
[London: John Murray, 1827]
- ASTRONOMY:
- As the diameter of the sun (883,000 miles) is 111 times greater than that
of the earth ... if there be any human inhabitants residing there, each individual
of moderate size must weigh at least two tons.
- There is no appearance of any water in the moon, nor of any atmosphere;
if any creatures, therefore, live in the moon, they must be very differently
constituted from the occupiers of the earth.
- Ceres (or the Piazzi) is about the size of
Ireland, which would make a similar appearance, were it dug out of the
ocean, and projected into the air.
- The two greatest Astronomical Discoveries: After Newton's discovery of the
elliptic orbits of the planets, La Grange's discovery of their periodical
inequalities is, without doubt, the noblest truth in physical astronomy; and with
respect to the doctrine of final causes, it may be regarded as the greatest of
all. (Copernicus's true theory of the solar system, was a discovery of the first
magnitude, but it was only theory not demonstration.)
- [T]he Brahmanical Hindoos seem to have formed their system when the
mean motion of Jupiter was slowest, and that of Saturn the most rapid; and the
two periods that fulfil these conditions, come very near to the year 3102 before
the Christian era, and to the year 1491 after it; both remarkable epochas
in the Astronomy of Hindostan.
- Sir Wm. Herschel considers the milky way to be an extensive branching
congeries of stars, within which our own solar system is placed; the luminous
tracts that constitute the galaxy being a projection of the nebulæ on
the concave surface of the sky, as seen from the solar system which it incloses.
- Moses says that light was first formed and that was the first day.
On the third day after this, the sun and moon were formed ... We may
therefore conclude that during the incipient formation of our planet,
it possessed a light peculiar to its own constitution, which appears also
to accompany other heavenly bodies, such as comets, in a similar stage
of their formation.
- GENERAL PHYSICS:
- Light moves at the rate of 170,000 miles per second.
- It has been observed that most of the agents we are acquainted with
require time to pass from one point of space to another; the force of
gravity may also be of this nature, and may not, any more than
light, be instantaneously transmitted from the sun to the planets, or from the
planets to one another. Is attraction a virtue propagated in time or
not; and if so, does it travel quicker or slower than light?
- An impression might be transmitted through the ocean from pole to
pole in the space of two hours and fifty-five minutes. Hence probably
originates the intumescence of the sea which commonly precedes a storm:
for supposing a storm to arise at the distance of 50 degrees of latitude, it
would not reach a certain spot in less than thirty hours, whereas the
agitation of the water would begin to be felt in 48 and two-thirds minutes.
- The strength of an ordinary man walking in horizontal direction, and with his
body inclining forward, is only equal to twenty-seven pounds, and it is known
by experience that a horse can draw horizontally as much as seven men.
- The thinnest substance ever observed is the aqueous film
of the soap bubble previous to its bursting, yet it is capable
of reflecting a faint image of a candle or of the sun. Hence its
thickness must correspond with what Sir Isaac Newton calls
the beginning of black, which appears in water at a
thickness of 1/750000th part of an inch.
- THERMAL PHYSICS:
- Nothing is known of the nature of heat, or of caloric, its
cause. Count Rumford has clearly proved that it has no weight ...
It is generally admitted, that the atoms of caloric are
attracted by every other substance, while they mutually repel
each other.
- It has been conjectured that there is a difference between solar
and terrestrial heat, the rays of the first passing through glass without
heating it, while the rays of the latter are stopped by the glass, which
becomes hot when opposed to them.
- It is known by experiment, that every sudden stroke,
every rapid motion, impressed on a mass of air which cannot
yield with sufficient quickness, excites in it a degree of light.
- Take a small tube, either of glass or metal, about three-eighths
of an inch in diameter, and four inches long, securely stopped
at one extremity. Fix a bit of dried fungus to the end of the
rammer, then thrust it smartly down the tube, and the heat of the
compressed air therein contained will cause the fungus to ignite.
[VIDEO]
- Of boiled potatoes, one per cent. to the bulk of water is put into
the boiler of the steam-engine, to prevent the cohesion of
the precipitated calcareous salts ... The boiler is emptied once
a month, and new potatoes added.
- Sir H. Davy melted two pieces of ice by their mutual friction,
in a room cooled below the freezing temperature.
- The greatest artificial cold that has yet been produced, was effected
by the mixture of diluted sulphuric acid with snow, which sunk Fahrenheit's
thermometer to minus 91 degrees.
- ATOMS & MOLECULES:
- It is the general opinion, that the elements of bodies consist of atoms
or extremely minute particles incapable of further division. It is
impossible to demonstrate the truth of this opinion, but it has been
almost universally admitted since the time of Bacon.
- The ultimate particles of matter never touch, however solid in appearance,
and no force can press them into real mathematical contact.
- [E]ach molecule is subject to the action of three forces:
- The attraction of the surrounding molecules.
- The attraction of the caloric of the same molecules.
- The repulsion of its caloric by the caloric of the other molecules.
The first two forces tend to make the particles approach each other,
and the third tends to separate them. The three states solid, fluid,
and gazeous, depend on the respective predominance of these
forces.
- The bodies which we at present call chemical elements are
probably all compounds.
- Mr. Dobreiner considers hydrogen gas as a metal dissolved in caloric.
- Oxygen, being a permanently elastic fluid, must consist of
atoms that repel each other; hence, a compound atom of oxygen, or a
number of atoms united together, seems quite impossible.
- Platinum is the heaviest body in nature.
- MATHEMATICS:
- + The sign of addition
- - The sign of subtraction
- = The sign of equality
- : The sign of arithmetical proportion disjunct
- :: The sign of identity of ratio
- × The sign of muliplication
- ÷ The sign of division
- @ The sign of involution
- ~ The sign of similitude
- √ The sign of radicality
- The phrase of "quantities less than nothing" has been
censured, yet there are correct ideas, which correct language
can hardly be made to express.
- If it be required to multiply 98,765 by 25, multiply first by 100
by adding two cyphers [i. e. zeroes], and then divide by 4.
- Binary division in arithmetic, consisting of halves, quarters,
eighths, sixteenths, &c., has always been found much more
convenient and more in unison with the habits of the people, than
the decimal division, which in France was found to produce great
frauds, in consequence of uneducated persons being incapable of
accurately distinguishing such divisions.
- PROBABILITY & STATISTICS:
- For the sake of easy calculation De Moivre assumed
86 as the boundary of human life, from which having
deducted the person's age (if 30 or upwards), the
half of the remainder is the average time that a man
may expect to live.
- The period of life at which man (under all circumstances)
has the probability of the greatest number of years to come,
is the age of 33.
- Chance very little disturbs events, which in their natural
constitution were designed to happen or fail according to some
determined law. It may produce the appearance of
inequality in the turning up of the head or reverse of a coin, still
the appearance, one way or another, will perpetually tend to
the proportion of equality.
- At whist, it is 12,211,799,222 to 1 that the dealer does not hold
12 trumps. It is 57 to 1 that he does hold 1 trump.
- In Bethlem Hospital, out of 265 lunatics, only 60 had red or light brown
hair; all the rest had dark hair.
- BIOLOGY:
- Life is something that prevents the chemical decomposition to which
dead animal and vegetable matter is subject, that regulates the temperature
of bodies, and is the cause of the actions we observe in them.
- When fish putrify, the light is not occasioned by the flesh of
the animal, but by numerous animalculæ whose
growth the putrefaction has promoted.
- It has been asserted that certain birds, not naturally aquatic, have, by living
a long time in marshes, become web-footed.
- The present object of the graziers in breeding Leicestershire sheep, is to
procure a breed with small heads and legs, but we must not suppose that
they can ever attain that degree of perfectibility as to make
heads and legs evanescent quantities.
- METAPHYSICS:
- Is absolute time any thing distinct from motion? But supposing
the earth, planets, &c. had been without motion from the creation,
still would not the duration of the state of rest have been equal to
the time which has elapsed since the creation?
- Everyone has his own measure of time in the quickness or
slowness with which his ideas succeed each other, for time appears
long to us when the ideas succeed each other rapidly in our minds,
and vice versâ.
- Time, abstracted from thoughts, actions, and motions, is actually
nothing, the succession of these being what we call time. Perhaps
this may account for the apparent sufferings of animals. The useful
and patient horse, which to us appears to suffer from ten to twenty
years of torture, perhaps, under this view of time, does not exist so
many months. Supposing it possible that a man, during the course
of his life, could fix his mind on one idea, and keep steadily to it; to
him there would be no such thing as time.
- Every body must be imagined in space, and every feeling in
time.
- MISC.:
- Soda water, prepared in the best manner, ought to
contain a very small portion of carbonate of soda, which
has a tendency to correct acidity in the stomach. It should also
contain about eight times its own bulk of carbonic acid gas,
which is generated in the gazometer from chalk and diluted
sulphuric acid. Much that is sold under the name of soda
water, contains scarcely any soda, being merely water
impregnated with carbonic acid gas by means of a forcing
pump, and consequently liable to be contaminated by copper,
zinc, or lead, according to the vessels in which the condensation
is carried on.
- A pleasant saline draught is made by dissolving thirty
grains of carbonate of soda or potash, and twenty grains of
citric acid (acid of lemons -- in the sodaic powders of the
shops, tartaric acid, on account of its cheapness, is too often
substituted) in two separate glasses, mixing them, and drinking
them in a state of effervescence.
- Notwithstanding the pains taken and vast expense incurred, the French
metrical system has wholly failed of success in practice, and never was generally
adopted. It was found that the common people could not be brought to
understand the division by ten, nor to adopt the Greek terms then introduced.
- The steam engines in England represent the power of 320,000 horses,
equal to 1,920,000 men, and being in fact managed only 36,000 men, add
consequently to our population 1,884,000 men.
- Nothing is so ridiculous as to condemn a true magician to be burned,
for it must be presumed that he is able to extinguish the fire, and twist the
necks of his judges.