EltronBKP/ElectronA

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EltronBKP/ElectronA

This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.

Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.

Tape/disk:	Home » Personal collection » Acorn ADFS disks » Electron » Pixel_map.ADF
Filename:	EltronBKP/ElectronA
Read OK:	✔
File size:	1D09 bytes
Load address:	D6576
Exec address:	0000

File contents

�.........*.......*.......*.......*.......*.......*.......*.......*.......*.<
�CEThe Discovery of the Electron

	In 1897, ....

	The experimental work that led Thomson to this discovery was to
investigate the passage of electric current through gases at very low
pressures. It is thought that the first experiments on this complicated
and controversial subject were carried out by Hauksbee in 1709. He
evacuated a glass vessel to the lowest pressure available, then set up a
high electric field in the vessel using bodies charged by friction. He
noticed a coloured glow passing through the gas as the electrodes were
discharged. This occurred with a much lower electric field, and quite
different colours from those observed in sparks at atmospheric pressure.
This kind of phenomenon is now used in fluorescent lighting and in "neon"
signs.
	As time moved on, the quality of vacuum pumps improved, with the
development of the Topler pump and Sprengel pump in the mid-19th century
for example. Such apparatus allowed the coductivity of gases to be
investigated over a much wider range of pressures. As the pressure was
slowly decreased from that used in Hauksbee's experiments to around
0.05mmHg (7 Pa), the coloured glow in the discharge tube   started to
divide into "striations" with characteristic dark spaces near the  cathode.
When the pressure fell further, to around 0.01mmHg (1 Pa), the dark space
closest to the cathode, called the Crookes dark space, extended to fill
the entire tube, and a green fluorescence was seen on the walls of the
tube.
	This kind of discharge was first observed and investigated in 1859
by Julius Plucker. It was his pupil Hittorf who had the ingenious idea of
using tube with a large anode in the shape of a Maltese cross, and a small
disc-shaped cathode. When a potential difference was applied across the
high vacuum in the tube, he found that the green fluorescence was spread
almost uniformly across the end of the tube, except for a well-defined
shadow left by the Maltese cross. This suggested to Hittorf that the
fluorescence was caused by an interaction between the glass and some kind
of rays, which emanated from the cathode and travelled in straight lines
until their path was blocked. He continued the experiments by using
different shapes and materials in place of the Maltese cross, and found in
every case that the rays were blocked by the object, and a shadow was
formed on the glass.
	This famous experiment was taken up again and extended in 1876 by
Goldstein, who first gave these rays the modern name of "cathode rays".
Instead of Hittorf's small cathode and large Maltese  cross, Goldstein
used a large cathode with a small object blocking the rays. If the rays
behaved like light, we would expect a blurred shadow in this case, with a
large penumbra but no umbra. This would be analogous to the image seen by
a human eye focussing on a distant landscape while a small pin is held in
front of the eye - the image of the pin is blurred over the landscape as
light passes into the lens either side of it.
	However, he found the shadow in this case to be just as sharp as in
Hittorf's experiment. This suggested that the rays were not being emitted
in every direction from each part of the cathode, like the photons emitted
from an incandescent object or the light arriving at the surface of a
human eye. Instead they were emitted normally (perpendicular to the
surface of the cathode) from each point, so that the rays striking each
part of the Maltese cross were all travelling in the same direction.
Goldstein was himself unable to use this clue as to the nature of the
cathode rays. His view was that the rays were waves propagating like light, through
the aether - a medium thought to exist as a absolute rest
frame, through which all electric and magnetic fields were conveyed. It
was later proven by Michelson and Morley's experiment of 1887, and
justified by Einstein's special theory of relativity in 1905, that such a
medium does not exist. However, until the nature of the rays was finally
proven beyond doubt, most German physicists supported Goldstein's view.
	At the same time a completely different theory was being developed
by a number of British physicists to explain the properties of the cathode
rays. They thought that the rays were streams of some kind of particle,
though the nature of the particle was unknown. This theory had an
immediate advantage over that of Goldstein, in that the laws governing
particles were well known, while the properties of the aetherial waves
were a complete mystery. This enabled supporters of the particle thoery to
make predictions about the rays and to test the properties of the
particles.
	The first such experiment was carried out by Sir William Crookes,
who attempted  to detect any momentum carried by them. He placed an
extremely light wind vane in the path of the rays, and found that the vane
started to turn slowly as if bombarded by particles. It is now known that
this rotation was caused by the rays heating the surface of the vane, and
thus increasing the pressure of the gas next to it. This has little to do
with the particulate nature of the rays, but by  coincidence Crooke's
result steered him in the direction of a correct theory. This result, and
others which followed, were published in the Philosophical Transactions,
1879.
	Crookes's next, more important, observation has already been
mentioned. As the pressure in a gas discharge tube is decreased from
atmospheric pressure, we first find a glow coming from gas itself. This
glow recedes away from the cathode leaving a dark space (called the
Crookes dark space), which at very low pressure fills the entire tube. In
this state, only the walls of the tube will phosphoresce, not the gas.
Crookes suggested that the phosphorescence was caused by colliions between
the cathode ray particles and the gas molecules in the tube. The end of
the dark space would then represent the place where the rays are likely to
have their first collision with a gas molecule. That is, the length of the
dark space is a measure of the mean free path of a cathode ray particle
travelling through the gas concerned. This idea fitted well with the
pressure-variation of the dark space, and suggested to Crookes that the
rays could be some kind of molecules, whose motion conformed to the
kinetic theory of gases. As we now know, the rays are not composed of
molecules, but Crookes again provided vital evidence for the particle
theory. 
	Crookes also noticed that the rays could be deflected by a magnetic
field - he inferred this from the displacement of the phosphorescent patch
on the walls of the tube. This suggested that the rays may be carrying
some electric current, but he was unable to find any precise law relating the
deflection to the applied field. Furthermore, he suggested that if the
rays were carrying currents of charged particles, their path should be
strongly influenced by the position and shape of the anode. His
experiments showed that this was not the case, so the nature of the rays
was thrown into question once again.

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*
00000040  2e 2e 2a 2e 2e 2e 2e 2e  2e 2e 2a 2e 3c 0d 80 43  |..*.......*.<..C|
00000050  45 54 68 65 20 44 69 73  63 6f 76 65 72 79 20 6f  |EThe Discovery o|
00000060  66 20 74 68 65 20 45 6c  65 63 74 72 6f 6e 0d 0d  |f the Electron..|
00000070  09 49 6e 20 31 38 39 37  2c 20 2e 2e 2e 2e 0d 0d  |.In 1897, ......|
00000080  09 54 68 65 20 65 78 70  65 72 69 6d 65 6e 74 61  |.The experimenta|
00000090  6c 20 77 6f 72 6b 20 74  68 61 74 20 6c 65 64 1a  |l work that led.|
000000a0  20 54 68 6f 6d 73 6f 6e  1a 20 74 6f 1a 20 74 68  | Thomson. to. th|
000000b0  69 73 1a 20 64 69 73 63  6f 76 65 72 79 20 77 61  |is. discovery wa|
000000c0  73 20 74 6f 0d 69 6e 76  65 73 74 69 67 61 74 65  |s to.investigate|
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000000e0  66 20 65 6c 65 63 74 72  69 63 20 63 75 72 72 65  |f electric curre|
000000f0  6e 74 20 74 68 72 6f 75  67 68 20 67 61 73 65 73  |nt through gases|
00000100  1a 20 61 74 1a 20 76 65  72 79 1a 20 6c 6f 77 0d  |. at. very. low.|
00000110  70 72 65 73 73 75 72 65  73 2e 20 49 74 20 69 73  |pressures. It is|
00000120  1a 20 74 68 6f 75 67 68  74 1a 20 74 68 61 74 1a  |. thought. that.|
00000130  20 74 68 65 20 66 69 72  73 74 20 65 78 70 65 72  | the first exper|
00000140  69 6d 65 6e 74 73 20 6f  6e 20 74 68 69 73 20 63  |iments on this c|
00000150  6f 6d 70 6c 69 63 61 74  65 64 0d 61 6e 64 1a 20  |omplicated.and. |
00000160  63 6f 6e 74 72 6f 76 65  72 73 69 61 6c 1a 20 73  |controversial. s|
00000170  75 62 6a 65 63 74 1a 20  77 65 72 65 20 63 61 72  |ubject. were car|
00000180  72 69 65 64 20 6f 75 74  1a 20 62 79 1a 20 48 61  |ried out. by. Ha|
00000190  75 6b 73 62 65 65 1a 20  69 6e 1a 20 31 37 30 39  |uksbee. in. 1709|
000001a0  2e 1a 20 48 65 0d 65 76  61 63 75 61 74 65 64 20  |.. He.evacuated |
000001b0  61 20 67 6c 61 73 73 20  76 65 73 73 65 6c 1a 20  |a glass vessel. |
000001c0  74 6f 1a 20 74 68 65 20  6c 6f 77 65 73 74 20 70  |to. the lowest p|
000001d0  72 65 73 73 75 72 65 20  61 76 61 69 6c 61 62 6c  |ressure availabl|
000001e0  65 2c 20 74 68 65 6e 20  73 65 74 20 75 70 20 61  |e, then set up a|
000001f0  0d 68 69 67 68 20 65 6c  65 63 74 72 69 63 20 66  |.high electric f|
00000200  69 65 6c 64 20 69 6e 20  74 68 65 1a 20 76 65 73  |ield in the. ves|
00000210  73 65 6c 1a 20 75 73 69  6e 67 1a 20 62 6f 64 69  |sel. using. bodi|
00000220  65 73 1a 20 63 68 61 72  67 65 64 20 62 79 20 66  |es. charged by f|
00000230  72 69 63 74 69 6f 6e 2e  20 48 65 0d 6e 6f 74 69  |riction. He.noti|
00000240  63 65 64 1a 20 61 20 63  6f 6c 6f 75 72 65 64 20  |ced. a coloured |
00000250  67 6c 6f 77 20 70 61 73  73 69 6e 67 20 74 68 72  |glow passing thr|
00000260  6f 75 67 68 20 74 68 65  20 67 61 73 20 61 73 1a  |ough the gas as.|
00000270  20 74 68 65 1a 20 65 6c  65 63 74 72 6f 64 65 73  | the. electrodes|
00000280  1a 20 77 65 72 65 0d 64  69 73 63 68 61 72 67 65  |. were.discharge|
00000290  64 2e 20 54 68 69 73 20  6f 63 63 75 72 72 65 64  |d. This occurred|
000002a0  1a 20 77 69 74 68 1a 20  61 1a 20 6d 75 63 68 1a  |. with. a. much.|
000002b0  20 6c 6f 77 65 72 1a 20  65 6c 65 63 74 72 69 63  | lower. electric|
000002c0  20 66 69 65 6c 64 2c 20  61 6e 64 20 71 75 69 74  | field, and quit|
000002d0  65 0d 64 69 66 66 65 72  65 6e 74 20 63 6f 6c 6f  |e.different colo|
000002e0  75 72 73 20 66 72 6f 6d  20 74 68 6f 73 65 20 6f  |urs from those o|
000002f0  62 73 65 72 76 65 64 1a  20 69 6e 1a 20 73 70 61  |bserved. in. spa|
00000300  72 6b 73 20 61 74 20 61  74 6d 6f 73 70 68 65 72  |rks at atmospher|
00000310  69 63 20 70 72 65 73 73  75 72 65 2e 0d 54 68 69  |ic pressure..Thi|
00000320  73 20 6b 69 6e 64 20 6f  66 20 70 68 65 6e 6f 6d  |s kind of phenom|
00000330  65 6e 6f 6e 20 69 73 20  6e 6f 77 20 75 73 65 64  |enon is now used|
00000340  1a 20 69 6e 20 66 6c 75  6f 72 65 73 63 65 6e 74  |. in fluorescent|
00000350  20 6c 69 67 68 74 69 6e  67 20 61 6e 64 20 69 6e  | lighting and in|
00000360  20 22 6e 65 6f 6e 22 0d  73 69 67 6e 73 2e 0d 09  | "neon".signs...|
00000370  41 73 20 74 69 6d 65 20  6d 6f 76 65 64 20 6f 6e  |As time moved on|
00000380  2c 20 74 68 65 20 71 75  61 6c 69 74 79 20 6f 66  |, the quality of|
00000390  20 76 61 63 75 75 6d 1a  20 70 75 6d 70 73 1a 20  | vacuum. pumps. |
000003a0  69 6d 70 72 6f 76 65 64  2c 1a 20 77 69 74 68 20  |improved,. with |
000003b0  74 68 65 0d 64 65 76 65  6c 6f 70 6d 65 6e 74 20  |the.development |
000003c0  6f 66 20 74 68 65 20 54  6f 70 6c 65 72 20 70 75  |of the Topler pu|
000003d0  6d 70 1a 20 61 6e 64 1a  20 53 70 72 65 6e 67 65  |mp. and. Sprenge|
000003e0  6c 20 70 75 6d 70 20 69  6e 20 74 68 65 20 6d 69  |l pump in the mi|
000003f0  64 2d 31 39 74 68 20 63  65 6e 74 75 72 79 0d 66  |d-19th century.f|
00000400  6f 72 1a 20 65 78 61 6d  70 6c 65 2e 1a 20 53 75  |or. example.. Su|
00000410  63 68 1a 20 61 70 70 61  72 61 74 75 73 1a 20 61  |ch. apparatus. a|
00000420  6c 6c 6f 77 65 64 20 74  68 65 20 63 6f 64 75 63  |llowed the coduc|
00000430  74 69 76 69 74 79 1a 20  6f 66 1a 20 67 61 73 65  |tivity. of. gase|
00000440  73 1a 20 74 6f 1a 20 62  65 0d 69 6e 76 65 73 74  |s. to. be.invest|
00000450  69 67 61 74 65 64 20 6f  76 65 72 20 61 20 6d 75  |igated over a mu|
00000460  63 68 20 77 69 64 65 72  1a 20 72 61 6e 67 65 1a  |ch wider. range.|
00000470  20 6f 66 1a 20 70 72 65  73 73 75 72 65 73 2e 1a  | of. pressures..|
00000480  20 41 73 20 74 68 65 20  70 72 65 73 73 75 72 65  | As the pressure|
00000490  20 77 61 73 0d 73 6c 6f  77 6c 79 1a 20 64 65 63  | was.slowly. dec|
000004a0  72 65 61 73 65 64 1a 20  66 72 6f 6d 1a 20 74 68  |reased. from. th|
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000004c0  75 6b 73 62 65 65 27 73  1a 20 65 78 70 65 72 69  |uksbee's. experi|
000004d0  6d 65 6e 74 73 20 74 6f  20 61 72 6f 75 6e 64 0d  |ments to around.|
000004e0  30 2e 30 35 6d 6d 48 67  20 28 37 20 50 61 29 2c  |0.05mmHg (7 Pa),|
000004f0  20 74 68 65 20 63 6f 6c  6f 75 72 65 64 1a 20 67  | the coloured. g|
00000500  6c 6f 77 1a 20 69 6e 1a  20 74 68 65 1a 20 64 69  |low. in. the. di|
00000510  73 63 68 61 72 67 65 1a  20 74 75 62 65 20 20 20  |scharge. tube   |
00000520  73 74 61 72 74 65 64 20  74 6f 0d 64 69 76 69 64  |started to.divid|
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00000540  6e 73 22 20 77 69 74 68  20 63 68 61 72 61 63 74  |ns" with charact|
00000550  65 72 69 73 74 69 63 20  64 61 72 6b 20 73 70 61  |eristic dark spa|
00000560  63 65 73 20 6e 65 61 72  20 74 68 65 20 20 63 61  |ces near the  ca|
00000570  74 68 6f 64 65 2e 0d 57  68 65 6e 20 74 68 65 20  |thode..When the |
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000005b0  29 2c 20 74 68 65 20 64  61 72 6b 20 73 70 61 63  |), the dark spac|
000005c0  65 0d 63 6c 6f 73 65 73  74 20 74 6f 20 74 68 65  |e.closest to the|
000005d0  20 63 61 74 68 6f 64 65  2c 20 63 61 6c 6c 65 64  | cathode, called|
000005e0  1a 20 74 68 65 1a 20 43  72 6f 6f 6b 65 73 1a 20  |. the. Crookes. |
000005f0  64 61 72 6b 20 73 70 61  63 65 2c 20 65 78 74 65  |dark space, exte|
00000600  6e 64 65 64 20 74 6f 20  66 69 6c 6c 0d 74 68 65  |nded to fill.the|
00000610  20 65 6e 74 69 72 65 20  74 75 62 65 2c 20 61 6e  | entire tube, an|
00000620  64 20 61 20 67 72 65 65  6e 20 66 6c 75 6f 72 65  |d a green fluore|
00000630  73 63 65 6e 63 65 20 77  61 73 1a 20 73 65 65 6e  |scence was. seen|
00000640  1a 20 6f 6e 1a 20 74 68  65 1a 20 77 61 6c 6c 73  |. on. the. walls|
00000650  20 6f 66 20 74 68 65 0d  74 75 62 65 2e 0d 09 54  | of the.tube...T|
00000660  68 69 73 20 6b 69 6e 64  20 6f 66 20 64 69 73 63  |his kind of disc|
00000670  68 61 72 67 65 20 77 61  73 1a 20 66 69 72 73 74  |harge was. first|
00000680  20 6f 62 73 65 72 76 65  64 20 61 6e 64 20 69 6e  | observed and in|
00000690  76 65 73 74 69 67 61 74  65 64 20 69 6e 20 31 38  |vestigated in 18|
000006a0  35 39 0d 62 79 20 4a 75  6c 69 75 73 20 50 6c 75  |59.by Julius Plu|
000006b0  63 6b 65 72 2e 20 49 74  20 77 61 73 20 68 69 73  |cker. It was his|
000006c0  1a 20 70 75 70 69 6c 20  48 69 74 74 6f 72 66 20  |. pupil Hittorf |
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000006f0  69 6e 67 20 74 75 62 65  20 77 69 74 68 20 61 20  |ing tube with a |
00000700  6c 61 72 67 65 20 61 6e  6f 64 65 20 69 6e 20 74  |large anode in t|
00000710  68 65 20 73 68 61 70 65  20 6f 66 20 61 20 4d 61  |he shape of a Ma|
00000720  6c 74 65 73 65 20 63 72  6f 73 73 2c 20 61 6e 64  |ltese cross, and|
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00000780  74 68 65 0d 68 69 67 68  1a 20 76 61 63 75 75 6d  |the.high. vacuum|
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000007a0  65 20 66 6f 75 6e 64 20  74 68 61 74 20 74 68 65  |e found that the|
000007b0  20 67 72 65 65 6e 20 66  6c 75 6f 72 65 73 63 65  | green fluoresce|
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000007d0  6c 6d 6f 73 74 20 75 6e  69 66 6f 72 6d 6c 79 20  |lmost uniformly |
000007e0  61 63 72 6f 73 73 1a 20  74 68 65 1a 20 65 6e 64  |across. the. end|
000007f0  1a 20 6f 66 1a 20 74 68  65 20 74 75 62 65 2c 20  |. of. the tube, |
00000800  65 78 63 65 70 74 20 66  6f 72 20 61 20 77 65 6c  |except for a wel|
00000810  6c 2d 64 65 66 69 6e 65  64 0d 73 68 61 64 6f 77  |l-defined.shadow|
00000820  1a 20 6c 65 66 74 20 62  79 20 74 68 65 20 4d 61  |. left by the Ma|
00000830  6c 74 65 73 65 20 63 72  6f 73 73 2e 20 54 68 69  |ltese cross. Thi|
00000840  73 1a 20 73 75 67 67 65  73 74 65 64 1a 20 74 6f  |s. suggested. to|
00000850  1a 20 48 69 74 74 6f 72  66 1a 20 74 68 61 74 1a  |. Hittorf. that.|
00000860  20 74 68 65 0d 66 6c 75  6f 72 65 73 63 65 6e 63  | the.fluorescenc|
00000870  65 20 77 61 73 1a 20 63  61 75 73 65 64 20 62 79  |e was. caused by|
00000880  20 61 6e 20 69 6e 74 65  72 61 63 74 69 6f 6e 20  | an interaction |
00000890  62 65 74 77 65 65 6e 20  74 68 65 20 67 6c 61 73  |between the glas|
000008a0  73 20 61 6e 64 20 73 6f  6d 65 20 6b 69 6e 64 0d  |s and some kind.|
000008b0  6f 66 20 72 61 79 73 2c  20 77 68 69 63 68 1a 20  |of rays, which. |
000008c0  65 6d 61 6e 61 74 65 64  1a 20 66 72 6f 6d 20 74  |emanated. from t|
000008d0  68 65 20 63 61 74 68 6f  64 65 20 61 6e 64 20 74  |he cathode and t|
000008e0  72 61 76 65 6c 6c 65 64  20 69 6e 20 73 74 72 61  |ravelled in stra|
000008f0  69 67 68 74 20 6c 69 6e  65 73 0d 75 6e 74 69 6c  |ight lines.until|
00000900  1a 20 74 68 65 69 72 20  70 61 74 68 20 77 61 73  |. their path was|
00000910  20 62 6c 6f 63 6b 65 64  2e 1a 20 48 65 1a 20 63  | blocked.. He. c|
00000920  6f 6e 74 69 6e 75 65 64  1a 20 74 68 65 1a 20 65  |ontinued. the. e|
00000930  78 70 65 72 69 6d 65 6e  74 73 1a 20 62 79 1a 20  |xperiments. by. |
00000940  75 73 69 6e 67 0d 64 69  66 66 65 72 65 6e 74 20  |using.different |
00000950  73 68 61 70 65 73 20 61  6e 64 20 6d 61 74 65 72  |shapes and mater|
00000960  69 61 6c 73 20 69 6e 20  70 6c 61 63 65 20 6f 66  |ials in place of|
00000970  20 74 68 65 20 4d 61 6c  74 65 73 65 20 63 72 6f  | the Maltese cro|
00000980  73 73 2c 20 61 6e 64 20  66 6f 75 6e 64 20 69 6e  |ss, and found in|
00000990  0d 65 76 65 72 79 20 63  61 73 65 1a 20 74 68 61  |.every case. tha|
000009a0  74 1a 20 74 68 65 1a 20  72 61 79 73 1a 20 77 65  |t. the. rays. we|
000009b0  72 65 1a 20 62 6c 6f 63  6b 65 64 20 62 79 20 74  |re. blocked by t|
000009c0  68 65 20 6f 62 6a 65 63  74 2c 20 61 6e 64 20 61  |he object, and a|
000009d0  20 73 68 61 64 6f 77 20  77 61 73 0d 66 6f 72 6d  | shadow was.form|
000009e0  65 64 20 6f 6e 20 74 68  65 20 67 6c 61 73 73 2e  |ed on the glass.|
000009f0  0d 09 54 68 69 73 20 66  61 6d 6f 75 73 20 65 78  |..This famous ex|
00000a00  70 65 72 69 6d 65 6e 74  20 77 61 73 20 74 61 6b  |periment was tak|
00000a10  65 6e 1a 20 75 70 1a 20  61 67 61 69 6e 20 61 6e  |en. up. again an|
00000a20  64 20 65 78 74 65 6e 64  65 64 20 69 6e 20 31 38  |d extended in 18|
00000a30  37 36 20 62 79 0d 47 6f  6c 64 73 74 65 69 6e 2c  |76 by.Goldstein,|
00000a40  20 77 68 6f 20 66 69 72  73 74 20 67 61 76 65 20  | who first gave |
00000a50  74 68 65 73 65 20 72 61  79 73 20 74 68 65 1a 20  |these rays the. |
00000a60  6d 6f 64 65 72 6e 1a 20  6e 61 6d 65 1a 20 6f 66  |modern. name. of|
00000a70  20 22 63 61 74 68 6f 64  65 20 72 61 79 73 22 2e  | "cathode rays".|
00000a80  0d 49 6e 73 74 65 61 64  1a 20 6f 66 1a 20 48 69  |.Instead. of. Hi|
00000a90  74 74 6f 72 66 27 73 1a  20 73 6d 61 6c 6c 1a 20  |ttorf's. small. |
00000aa0  63 61 74 68 6f 64 65 20  61 6e 64 20 6c 61 72 67  |cathode and larg|
00000ab0  65 20 4d 61 6c 74 65 73  65 20 20 63 72 6f 73 73  |e Maltese  cross|
00000ac0  2c 20 47 6f 6c 64 73 74  65 69 6e 0d 75 73 65 64  |, Goldstein.used|
00000ad0  20 61 20 6c 61 72 67 65  20 63 61 74 68 6f 64 65  | a large cathode|
00000ae0  20 77 69 74 68 1a 20 61  1a 20 73 6d 61 6c 6c 1a  | with. a. small.|
00000af0  20 6f 62 6a 65 63 74 20  62 6c 6f 63 6b 69 6e 67  | object blocking|
00000b00  20 74 68 65 20 72 61 79  73 2e 20 49 66 20 74 68  | the rays. If th|
00000b10  65 20 72 61 79 73 0d 62  65 68 61 76 65 64 20 6c  |e rays.behaved l|
00000b20  69 6b 65 20 6c 69 67 68  74 2c 20 77 65 20 77 6f  |ike light, we wo|
00000b30  75 6c 64 20 65 78 70 65  63 74 20 61 20 62 6c 75  |uld expect a blu|
00000b40  72 72 65 64 1a 20 73 68  61 64 6f 77 20 69 6e 20  |rred. shadow in |
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00001a00  65 73 2e 20 41 73 20 77  65 1a 20 6e 6f 77 1a 20  |es. As we. now. |
00001a10  6b 6e 6f 77 2c 1a 20 74  68 65 1a 20 72 61 79 73  |know,. the. rays|
00001a20  1a 20 61 72 65 20 6e 6f  74 20 63 6f 6d 70 6f 73  |. are not compos|
00001a30  65 64 20 6f 66 0d 6d 6f  6c 65 63 75 6c 65 73 2c  |ed of.molecules,|
00001a40  1a 20 62 75 74 1a 20 43  72 6f 6f 6b 65 73 1a 20  |. but. Crookes. |
00001a50  61 67 61 69 6e 1a 20 70  72 6f 76 69 64 65 64 1a  |again. provided.|
00001a60  20 76 69 74 61 6c 20 65  76 69 64 65 6e 63 65 20  | vital evidence |
00001a70  66 6f 72 20 74 68 65 20  70 61 72 74 69 63 6c 65  |for the particle|
00001a80  0d 74 68 65 6f 72 79 2e  20 0d 09 43 72 6f 6f 6b  |.theory. ..Crook|
00001a90  65 73 20 61 6c 73 6f 20  6e 6f 74 69 63 65 64 20  |es also noticed |
00001aa0  74 68 61 74 20 74 68 65  20 72 61 79 73 20 63 6f  |that the rays co|
00001ab0  75 6c 64 20 62 65 20 64  65 66 6c 65 63 74 65 64  |uld be deflected|
00001ac0  20 62 79 20 61 20 6d 61  67 6e 65 74 69 63 0d 66  | by a magnetic.f|
00001ad0  69 65 6c 64 20 2d 20 68  65 20 69 6e 66 65 72 72  |ield - he inferr|
00001ae0  65 64 20 74 68 69 73 20  66 72 6f 6d 20 74 68 65  |ed this from the|
00001af0  20 64 69 73 70 6c 61 63  65 6d 65 6e 74 20 6f 66  | displacement of|
00001b00  20 74 68 65 20 70 68 6f  73 70 68 6f 72 65 73 63  | the phosphoresc|
00001b10  65 6e 74 20 70 61 74 63  68 0d 6f 6e 20 74 68 65  |ent patch.on the|
00001b20  20 77 61 6c 6c 73 20 6f  66 20 74 68 65 1a 20 74  | walls of the. t|
00001b30  75 62 65 2e 1a 20 54 68  69 73 1a 20 73 75 67 67  |ube.. This. sugg|
00001b40  65 73 74 65 64 1a 20 74  68 61 74 20 74 68 65 20  |ested. that the |
00001b50  72 61 79 73 20 6d 61 79  20 62 65 20 63 61 72 72  |rays may be carr|
00001b60  79 69 6e 67 0d 73 6f 6d  65 1a 20 65 6c 65 63 74  |ying.some. elect|
00001b70  72 69 63 20 63 75 72 72  65 6e 74 2c 20 62 75 74  |ric current, but|
00001b80  20 68 65 20 77 61 73 20  75 6e 61 62 6c 65 20 74  | he was unable t|
00001b90  6f 20 66 69 6e 64 1a 20  61 6e 79 1a 20 70 72 65  |o find. any. pre|
00001ba0  63 69 73 65 20 6c 61 77  1a 20 72 65 6c 61 74 69  |cise law. relati|
00001bb0  6e 67 1a 20 74 68 65 0d  64 65 66 6c 65 63 74 69  |ng. the.deflecti|
00001bc0  6f 6e 20 74 6f 1a 20 74  68 65 1a 20 61 70 70 6c  |on to. the. appl|
00001bd0  69 65 64 1a 20 66 69 65  6c 64 2e 1a 20 46 75 72  |ied. field.. Fur|
00001be0  74 68 65 72 6d 6f 72 65  2c 20 68 65 20 73 75 67  |thermore, he sug|
00001bf0  67 65 73 74 65 64 20 74  68 61 74 20 69 66 20 74  |gested that if t|
00001c00  68 65 0d 72 61 79 73 20  77 65 72 65 20 63 61 72  |he.rays were car|
00001c10  72 79 69 6e 67 20 63 75  72 72 65 6e 74 73 20 6f  |rying currents o|
00001c20  66 20 63 68 61 72 67 65  64 1a 20 70 61 72 74 69  |f charged. parti|
00001c30  63 6c 65 73 2c 1a 20 74  68 65 69 72 1a 20 70 61  |cles,. their. pa|
00001c40  74 68 1a 20 73 68 6f 75  6c 64 20 62 65 0d 73 74  |th. should be.st|
00001c50  72 6f 6e 67 6c 79 1a 1a  20 69 6e 66 6c 75 65 6e  |rongly.. influen|
00001c60  63 65 64 1a 20 62 79 1a  20 74 68 65 1a 20 70 6f  |ced. by. the. po|
00001c70  73 69 74 69 6f 6e 1a 20  61 6e 64 1a 20 73 68 61  |sition. and. sha|
00001c80  70 65 1a 20 6f 66 1a 20  74 68 65 1a 20 61 6e 6f  |pe. of. the. ano|
00001c90  64 65 2e 1a 20 48 69 73  0d 65 78 70 65 72 69 6d  |de.. His.experim|
00001ca0  65 6e 74 73 20 73 68 6f  77 65 64 20 74 68 61 74  |ents showed that|
00001cb0  20 74 68 69 73 20 77 61  73 20 6e 6f 74 1a 20 74  | this was not. t|
00001cc0  68 65 1a 20 63 61 73 65  2c 20 73 6f 20 74 68 65  |he. case, so the|
00001cd0  20 6e 61 74 75 72 65 20  6f 66 20 74 68 65 20 72  | nature of the r|
00001ce0  61 79 73 0d 77 61 73 20  74 68 72 6f 77 6e 20 69  |ays.was thrown i|
00001cf0  6e 74 6f 20 71 75 65 73  74 69 6f 6e 20 6f 6e 63  |nto question onc|
00001d00  65 20 61 67 61 69 6e 2e  0d                       |e again..|
00001d09

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