 atmospheric pressure.
(31) Pressure of Air.—The increase in volume of the inclosed air, and consequent decrease in its pressure, may be illustrated by inserting a tube, blown into a bulb at one end, full of air, and with its open mouth downwards in a vessel containing water, which is placed under the receiver of the pump. With each movement of the piston, the air in the bulb expands, while a portion of it in the act of expanding escapes, and bubbles up through the water. An amusing variation of this experiment may be made by placing a number of shrivelled apples in the receiver, and then working the pump. The apples contain air in their pores, which is prevented from escaping by the rind; on working the pump the diminished pressure causes this imprisoned air to expand; in consequence, the apples swell up, and regain their fresh and plump appearance. The illusion vanishes the moment the atmospheric air is readmitted, because the pressure of the external air reduces that in the apples to its former bulk. The pressure thus exhibited is very considerable, as may be shown by the following experiment. Take a thin vessel, such as a light flask, and seal it up full of air; now if the air be exhausted from a receiver placed over it, the flask will be burst into fragments. The great pressure which air exerts against the internal surface of the vessels in which it is contained, may also be exhibited by allowing a weight of several pounds to rest upon a bladder placed under the receiver of the air-pump; on exhausting the air from the receiver, the air in the bladder expands, and lifts the weight.
capable of being brought suddenly into exercise. Instances of this kind are furnished in the compressed air-fountain, and in the common forcing-pump, one variety of which constitutes that invaluable machine, the fire-engine. A still more striking illustration is seen in the air-gun, where the power of compressed air is made to execute the office of ordinary gunpowder, a substance which may be regarded as a magazine of condensed air which can be brought into action at will.
this purpose a well-shaped globular flask, P, fig. 13, furnished with a small stop-cock, is screwed to the plate of the pump, and the air is exhausted. In this state it is transferred to a good balance and accurately counterpoised; it is then attached to a graduated jar, G, filled with air, also provided with a stop-cock, and standing over water; the moment that, by opening the stop-cocks, a communication is made between the jar and the flask, the air rushes into the exhausted vessel. The amount that thus enters is read off by noticing the level of the water before the stopcocks are opened, and then estimating its rise afterwards by the marks on the side of the jar. On transferring the flask back to the balance, it will be found to have increased in weight several grains.
Minute attention to a variety of circumstances is required to insure a correct result in this experiment. It is by experiments conducted on this principle that the density of the air has been well ascertained (146).
According to Prout, 100 cubic inches of air at a temperature of 6o° F., when the column of mercury in the barometer stands at 30 inches, are 3roil7 grains. Regnault found that 1 litre of air at o° C, was (barometer 76omm-, also at o° C.) 1*293187 grammes. This, if reduced to the English standards, would make the 100 cubic inches of air amount to 30^93 8 grains,* or 13 cubic feet of air would be about 1 lb.
Air at o" C. Water at 40 C. Mercury at o° C.
32*809 feet square, and 16-4045 feet high, with a cubic content of 17658*3 cub. feet, and the air that it contains at 6o° P. and 30 in. barometer, would be about 1349 lb. or 12 cwt.
It is obvious that if, in the experiment with the flask, just described, the graduated jar had contained any other gas instead of atmospheric air, it would be possible to ascertain the weight of a given quantity of such gas; and by comparing this weight with that of an equal volume of air, to ascertain its density.
The list of drivers' salaries has been published. Business Book GP conducts an annual survey of the financial flows within Formula 1 and always comes up with a list of the best-earning drivers at the end of the season.
It will come as no surprise that Lewis Hamilton is the best paid driver in Formula 1. According to Business Book GP, Hamilton will receive a salary of €47 million in 2020. However, this is the basic salary. Bonuses and sponsorship money are not included in the list, reported Motorsport.com.
The other big earners in the sport are Sebastian Vettel (35 million), Daniel Ricciardo (20 million) and Max Verstappen (16 million). The worst paid driver on the grid is Antonio Giovinazzi. He will earn 'only' EUR 500,000 this year from Alfa Romeo. Daniil Kvyat, George Russell and Nicholas Latifi are also below the million mark, with a salary of EUR 750 000.
If we then compare the drivers' salaries with the number of points they have earned so far, you get a list of the drivers where the teams get the best value for money. Pierre Gasly then comes out on top, with a salary of EUR 15,873.02 per point achieved. Norris (€20,270.27 per point) and Stroll (€25,423.73 per point) also score well.
Romain Grosjean, Sebastian Vettel, Kimi Raikkonen and Kevin Magnussen only score it and cost their teams between one and two million euros per point. Max Verstappen is a nice midfielder with a salary of 93,117.65 euros per point.
Paleontologist, oceanographer, tech innovator: these black women are doing life-changing work in STEM.
Loretta Cheeks: Cheeks has two decades of experience in computer science and engineering, developing systems and heading up development teams within the communications, radio, avionics, instrumentation and control, and chemical industries. She is currently a computer science Ph.D. candidate at Arizona State University. She also founded StrongTIES to promote STEM K-12 education.
Danielle Cummings: Cummings has a Ph.D. in computer science from Texas A&M University and is a computer systems researcher for the Department of Defense. She also is the founder of Black Women in Computing (BWiC).
Star Cunningham: Cunningham has an extensive computer science background including telecommunications product development, and as a solutions manager for IBM Smarter Planet. Currently, she is the founder and CEO of 4D Healthcare. Her company has developed an innovative solution for managing chronic pain and conditions.
Kala Fleming: Fleming is a scientist with IBM who leads research in water management. She develops solutions and leads projects that improve urban water security, agricultural water management, and public health.
Ayanna Howard: Howard is a respected roboticist and a Motorola Foundation professor in the School of Electrical and Computer Engineering at Georgia Tech’s Institute for Robotics and Intelligent Machines. She has created robots to study the impact of global warming on the Antarctic ice shelves.
Jedidah Isler: Isler made history as the first African American woman to receive a Ph.D. in Astrophysics. She is presently an NSF Astronomy & Astrophysics Postdoctoral Fellow at Vanderbilt University and participates in the Future Faculty Leader program at Harvard University’s Center for Astrophysics.
Hadiyah-Nicole Green: Green is a physicist who recently made groundbreaking headway in the use of lasers to treat cancer.
Ashanti Johnson: Johnson is a geochemist and chemical oceanographer. One of the first African American women to earn a Ph.D. in oceanography; her work was instrumental in decoding the environmental effects of potentially hazardous incidents throughout Puerto Rico and in the aftermath of the Chernobyl nuclear accident.
Nashlie H. Sephus: Sephus is the CTO of tech startup, Partpic, an app which lets users find replacement parts for various products via a photo. Sephus is the brain power behind this technology; she writes the visual recognition algorithms for the app.
Lisa White:White is Director of Education and Outreach at the University of California Museum of Paleontology and Adjunct Professor of Geology at San Francisco State University. She is a micropaleontologist (specializing in fossil diatoms) and she is active in efforts to increase diversity in the geosciences through programs such as SF-ROCKS (Reaching Out to Communities and Kids with Science in San Francisco). She was the inaugural recipient of the Geological Society of America Bromery Award, an honor bestowed upon a geoscientist who has been instrumental in opening the geoscience field to other minorities.Our covered bridge
Book
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When we think of pioneers, we generally picture the vast reaches of the Old West. However, there are many other parts of our country which have as glorious and colorful a past as the sections west of the Mississippi. It is one of these little-known lands of Northern New York on the Canadian border that Florence Kelly writes about in this absorbing and memorable book containing stories from and around Cook's Corners, NY.
Available copies
- 1 of 1 copy available at OWWL.A somewhat disappointing metaphysical rehash from Kress.
This does read like it is stretched, too, and gets tedious at