The electron microscope was only possible with the development of high vacuum technology. Mechanical pumps were available early in this century, and Gaede in Germany developed the mercury pump called a “condensation pump” during WWI and in the 1920's. In 1928, Burch in England found that a low vapor pressure oil would work in a mercury pump and the oil diffusion pump was born. They were made by DPI in Rochester, Metropolitan Vickers in England, and Leyboid in Germany. Other oils became available and in the mid-30's, vacuum evaporators were in laboratory use in England, Germany and the United States.

In the 1930's and 40's, the aim was to produce vacuum of 10-4 - 10-5 mm Hg where the mean free path was two feet or more and atoms, molecules and electrons could move this distance with little obstruction. In those days, we were all very happy to get 10-4 - 10-5 without worrying much as to what gas was left.

The microscope has always played an important part in the field of environmental science. Initially it was involved mostly with those who analyzed for biological indicators of pollution or those who examined air pollution particles, but more recently it is being used by a large number of analysts of particulate samples following the concern over asbestos in schools. With the Asbestos Hazard Emergency Response Act (AHERA) of 1987, transmission electron microscopy (TEM) formally joined polarized light microscopy (PLM) and phase contrast microscopy (PCM) as a recognized regulation-required standard procedure for the analysis of asbestos. While asbestos remains a considerable activity in environmental microscopy, other areas including analysis of nan-asbestos fibers such as ceramic fibers, lead particle source determination, respirable silica measurement, and indoor air qualify particle examination have seen some interesting developments.

What is industrial mineral microscopy? It is the application of any micro-analytical technique used to characterize and identify non-metallic and non-fuel earth materials. Humans have used industrial minerals since ancient times. The earliest known scientific work which dealt expressly with minerals and artificial products derived from them is Theophrastus On Stones. Theophrastus, a pupil and friend of Aristotle, described the use of fuller's earth and gypsum for whitening discolored cloth garments in the latter half of the 4th century, B.C. Fuller's earth is still used today as a decolorizing agent by manufacturers of oil and fat products. Gypsum, of course, is widely used in plaster of paris, cement, and paper.

Today, industrial minerals are encountered often by people in everyday life. Electronic, pharmaceutical, cosmetic, construction, paper, and plastics industries use industrial minerals in a multitude of products.

Although it has been possible for many years to determine the average position of atoms by using diffraction techniques, finding the positions of specific atoms has been an elusive target. This latter goal is now in sight. Individual atoms on surfaces were first seen in the seventies by the Chicago Group using the then newly invented Scanning Transmission Electron Microscope (STEM). More recently atoms on surfaces have also been seen by Scanning Tunneling Microscopy (STM) and associated variants (e.g. Atomic Force Microscopy). Atomic structures in the interior of a material have been imaged in recent years through atomic resolution transmission electron microscopy of thin film specimens. Progress in these developments is following an acceleration path and the Materials Research Division of the NSF recently commissioned a panel to review the area and provide advice on an appropriate response.

Let's face it, nobody became a microscopist because they wanted to become an expert in Vacuum Science. The fact is that most of us were shown the proverbial “fly's eye” micrograph and fancied ourselves as the Ansel Adams of Electron Microscopy. As a consequence, during the progress of our careers, we have had to come to grips with Vacuum Science, usually on a “need to know” basis. Specifically, when the system has broken down, we need to know who can fix it … when they can fix it … and why they can not fix it sooner…

Nevertheless, the fact is that we ignore vacuum science at our peril. Although microscopes can withstand a lot of abuse before they catastrophically fail, they respond to poor vacuum practice with poor vacuum quality. In the final analysis ifs extremely valuable to have some “Vacuum sawy”.

Can you imagine the motivational value of a young adult being exposed to images of common day objects that they have an interest in, magnified ten, one hundred, or one thousand times? Then imagine the student learning the theory and operation of a scanning electron microscope. Finally, imagine walking into a laboratory to see these same students operating an SEM and taking their own micrographs.

For the past three years I have had the pleasure of teaching the laboratory portion of the SEMEDS program. The program's goal is not just to motivate high school students in science, but to expose them to the wonders of microscopy and how it affects their everyday life.

The program currently has three phases. During phase one, teachers from local high schools are contracted about the program. The teachers volunteer at the beginning of the school year then become students themselves during a four hour class.

Pittcon ‘93 marked the 10th anniversary of the introduction of a microscope attachment designed specifically for Fourier transform infrared microspectroscopy. The first commercial microscope developed for FT-IR spectroscopy was designed by Spectra-Tech, Inc., under the direction of then-owner D. W. Sting, in fulfillment of a contract with C. T. Foskett of the Digilab Division of BioRad. Digilab recognized a growing interest in the market for an FT-IR microscope and contracted with Spectra-Tech to design and build a microscope accessory for Digilab's FT-IR spectrometers. This microscope was introduced at the 1983 Pittsburgh Conference.

Linking microscopy with Fourier transform spectroscopy was a very significant event, but the foundation of infrared microspectroscopy can be traced back to 1949. The explosive growth in the use of infrared-absorption spectroscopy following World War II led researchers R. Gore (in the U.S.A.), and R. Barer, A. R. Cole, and H. W. Thompson (in England), to investigate (in 1949) the possibility of recording infrared spectra of microscopic samples.

Great strides have been made in the last decade in high resolution transmission electron microscopes (TEMs) which can also provide elemental information via energy dispersive X-ray analysis (EDX) or energy loss spectroscopy (EELS), and proponents of various TEM techniques make bold claims. Convergent beam elecjron diffraction and microdifff action shine as techniques for defect structure analysis and means for solving crystal structures. The spectroscopies can now be used to map chemical state information at a level which until recently might be encountered in science fiction. As a pure imaging device, electron holography holds great promise for providing Ehe ultimate (would you believe 0.1Å?) imaging resolution. Although conventional TEMs will never approach this, it appears that we are learning more and more about less and less, until we will soon know everything there is to know about nothing.

Pressure scales can be extremely confusing to new operators. This is not surprising. To my mind, there are three primary areas of confusion.

Firstly, the pressure of gas inside an instrument changes over many orders of magnitude during pumpdown. The change is about 9 orders of magnitude for a traditional Scanning Electron Microscope and about 13 orders of magnitude for an ultra-high vacuum instrument such as a Scanning Auger Microprobe.

To give an idea about the scale of change involved in vacuum, consider that the change in going from ambient pressure to that inside a typical ultra high vacuum system is like comparing one meter with the mean radius of the planet Pluto's orbit. The fact is that we don't often get to play with things on that scale. As a consequence, many of us have to keep reminding ourselves that 1 X 10-3 is one thousand times the value of 1 X 10-6 - not twice the value.

1992 was certainly a banner year for microscopy in terms of an incredible total of nearly 3000 presentations given world-wide - at the largest ever joint (E)MSA/MAS/MSC meeting in Boston and at the 3 IFSEM-sanctioned Regional Conferences in Spain, China and Venezuela. Several of the local affiliate societies also mounted well-attended symposia and contributed to the outpouring of words and images. The apparently continuously growing volume of microscopy-related presentations has impacted both conference organizers and publishers.

Poster presentations are being used to an increasing extent to avoid an excessive number of parallel sessions. There is also an economic incentive as a poster session probably costs the organizers less than half that of a platform session of contributed papers. The poster trend draws a mixed response. Most microscopists love to look at posters but hate to prepare them as they are much more work to put together and are costly. They are awkward to carry and often have a one-time use whereas slides are for ever.

The Microscopy Society of America (MSA) is beginning a long-term educational effort; the first goal of the program is to bring the excitement of microscopy to middle schools. We'll begin by developing a curriculum manual that integrates an understanding of how lenses magnify with observation of the microworld; examples will be from both physical and biological sciences. Funding will come from NSF and private foundations, and science education expertise will be provided by the Lawrence Hall of Science in Berkeley, a leading developer of science curriculum. As educators often use acronyms, we've named ours MICRO, for Microscopy In Curriculum - Research Outreach.

Writing a manual is just the beginning. MSA is directing its first effort at middle schools, because teachers at that level who want and need to teach science often lack the background to do so as anything more than a dull textbook exercise; teacher training workshops will be offered nationally.

While many of us have used a computer network to send E-mail, how about using it to remotely control an electron microscope? That's exactly what Telemicroscopy refers to.

Up to now electron microscopy (EM) has been conducted typically in a darkened enclosure, with the operator sitting in the dark for hours staring at a dim phosphor screen. This paradigm was not, however, closely followed during the telemicroscopy demonstration at the SIGGRAPH 1992 meeting in Chicago, where microscopic images were acquired on-line over the Internet high-speed computer network from the intermediate-high voltage electron microscope located at the San Diego Microscopy and Imaging Resource. Stereo-pairs were displayed on a color projection screen in front of many spectators and camera crews.