History of the Thermometer and Lord Kelvin

History of the Thermometer and Lord Kelvin Lord Kelvin invented the Kelvin Scale in 1848 used on thermometers. The Kelvin Scale measures the ultimate extremes of hot and cold. Kelvin developed the idea of absolute temperature, what is called the Second Law of Thermodynamics, and developed the dynamical theory of heat. In the 19th century, scientists were researching what was the lowest temperature possible. The Kelvin scale uses the same units as the Celcius scale, but it starts at ABSOLUTE ZERO, the temperature at which everything including air freezes solid. Absolute zero is O K, which is - 273 °C degrees Celsius. Lord Kelvin - Biography Sir William Thomson, Baron Kelvin of Largs, Lord Kelvin of Scotland (1824 - 1907) studied at Cambridge University, was a champion rower, and later became a Professor of Natural Philosophy at the University of Glasgow. Among his other achievements was the 1852 discovery of the Joule-Thomson Effect of gasses and his work on the first transatlantic telegraph cable (for which he was knighted), and his inventing of the mirror galvanometer used in cable signaling, the siphon recorder, the mechanical tide predictor, an improved ships compass. Extracts from: Philosophical Magazine October 1848 Cambridge University Press, 1882 ...The characteristic property of the scale which I now propose is, that all degrees have the same value; that is, that a unit of heat descending from a body A at the temperature T ° of this scale, to a body B at the temperature (T-1) °, would give out the same mechanical effect, whatever be the number T. This may justly be termed an absolute scale since its characteristic is quite independent of the physical properties of any specific substance. To compare this scale with that of the air-thermometer, the values (according to the principle of estimation stated above) of degrees of the air-thermometer must be known. Now an expression, obtained by Carnot from the consideration of his ideal steam-engine, enables us to calculate these values when the latent heat of a given volume and the pressure of saturated vapor at any temperature are experimentally determined. The determination of these elements is the principal object of Regnaults great work, already referred to, but, at present, his researches are not complete. In the first part, which alone has been as yet published, the latent heats of a given weight, and the pressures of saturated vapour at all temperatures between 0 ° and 230 ° (Cent. of the air-thermometer), have been ascertained; but it would be necessary in addition to know the densities of saturated vapour at different temperatures, to enable us to determine the latent heat of a given volume at any temperature. M. Regnault announces his intention of instituting researches for this object; but till the results are made known, we have no way of completing the data necessary for the present problem, except by estimating the density of saturated vapour at any temperature (the corresponding pressure being known by Regnaults researches already published) according to the approximate laws of compressibility and expansion (the laws of Mariotte and Gay-Lussac, or Boyle and Dalton). Within the limits of natural temperature in ordinary climates, the density of saturated vapour is actually found by Regnault (Études Hydromà ©triques in the Annales de Chimie) to verify very closely these laws; and we have reasons to believe from experiments which have been made by Gay-Lussac and others, that as high as the temperature 100 ° there can be no considerable deviation; but our estimate of the density of saturated vapour, founded on these laws, may be very erroneous at such high temperatures at 230 °. Hence a completely satisfactory calculation of the proposed scale cannot be made till after the additional experimental data shall have been obtained; but with the data which we actually possess, we may make an approximate comparison of the new scale with that of the air-thermometer, which at least between 0 ° and 100 ° will be tolerably satisfactory. The labour of performing the necessary calculations for effecting a comparison of the proposed scale with that of the air-thermometer, between the limits of 0 ° and 230 ° of the latter, has been kindly undertaken by Mr. William Steele, lately of Glasgow College, now of St. Peters College, Cambridge. His results in tabulated forms were laid before the Society, with a diagram, in which the comparison between the two scales is represented graphically. In the first table, the amounts of mechanical effect due to the descent of a unit of heat through the successive degrees of the air-thermometer are exhibited. The unit of heat adopted is the quantity necessary to elevate the temperature of a kilogramme of water from 0 ° to 1 ° of the air-thermometer; and the unit of mechanical effect is a metre-kilogramme; that is, a kilogramme raised a metre high. In the second table, the temperatures according to the proposed scale, which correspond to the different degrees of the air-thermometer from 0 ° to 230 °, are exhibited. The arbitrary points which coincide on the two scales are 0 ° and 100 °. If we add together the first hundred numbers given in the first table, we find 135.7 for the amount of work due to a unit of heat descending from a body A at 100 ° to B at 0 °. Now 79 such units of heat would, according to Dr. Black (his result being very slightly corrected by Regnault), melt a kilogramme of ice. Hence if the heat necessary to melt a pound of ice be now taken as unity, and if a metre-pound be taken as the unit of mechanical effect, the amount of work to be obtained by the descent of a unit of heat from 100 ° to 0 ° is 79x135.7, or 10,700 nearly. This is the same as 35,100 foot-pounds, which is a little more than the work of a one-horse-power engine (33,000 foot pounds) in a minute; and consequently, if we had a steam-engine working with perfect economy at one-horse-power, the boiler being at the temperature 100 °, and the condenser kept at 0 ° by a constant supply of ice, rather less than a pound of ice would be melted in a minute.

Starting A Copywriting Business

Starting A Copywriting Business Starting A Copywriting Business Starting A Copywriting Business By Ali Hale This is a guest article by Andy MacDonald. Today companies are realizing that cleverly written copy can seriously affect the responsiveness to their ads and marketing collateral. Online and offline content has to be designed in a cleverly written manner to induce the reader to purchase the business’s products or services, or otherwise do what the advertiser wants them to do. If you have excellent writing skills and have copywriting experience, this could be the ideal business venture for you. To start this type of business, you would need excellent writing skills and past experience with writing creative advertising copy. So let’s take a look at a few key areas involved in starting your own copywriting business. Since you are providing a service that has no inventory, your initial costs will be minimal. You will have to pay for the design, development, and hosting of your Web site. You will have to invest in an appropriate computer, software and a printer. Other costs that you will incur are associated with promoting your copywriting service online and offline. The cost to start this type of business will generally range from $4,000 to $10,000. (Note from the editor: I believe you could start operating with even less, perhaps $100. Setup a domain name with a free and clean WordPress theme and you are ready to go.) If you were starting this venture a home-based business you could run the business single handedly for as long as is necessary; however if you wanted to start this as a full-time business all you would need to get going is one full time employee. If your business requests exceed what you’re capable of handling, you might consider hiring an additional employee as and when required. This business has strong international potential, and with the presence of the Internet, its the kind of business which can be run from anywhere in the world. If you were fluent in other languages you could even advertise for copywriting jobs in other countries. This of course depends on your level of knowledge with the foreign languages and cultures. It is important to remember that if you are writing copy for a company from another culture, you should understand the culture for which you are writing the copy. In many instances advertising firms have designed and implemented a marketing campaign before understanding what the culture was all about. This has resulted in offending millions of individuals with advertisements that offend the home country’s culture. If you decide to take on any international projects, make sure you do your research first before you write your advertising copy. One bad experience could seriously hinder the future of your copywriting business. With the internet playing an ever-increasingly role in everyday life, there are now many ways you can advertise and promote your new business on and offline. Here are a few tips on where you should be promoting this type of business. Participate in newsgroups and discussion forums related to marketing and advertising with a cleverly designed signature file. Participating in advertising and marketing-related mailing lists would enable you to display your expertise while directing traffic to your Web site. Develop links from as many advertising, marketing, and business-service-related Web sites, meta-indexes, and directories as possible. Use caution with your link trading strategies though! Participate in marketing related e-zines through contribution of appropriate articles that feature your expertise and knowledge of your craft. And finally, a few tips on where you could earn additional income with this type of business; you might want to consider offering graphic design services to your clients. Since this would complement your copywriting service, you would be able to develop extensive promotional pieces for your clients. Another option is to offer ghost-writing services, press release services, advertising copy, marketing copy and any number of other related topics. Copywriting is now big business both on and off the internet. Advertisers are increasingly looking to skilled copywriters to craft their promotional copy, trying to gain every edge over their competitor. A highly skilled copywriter can earn thousands of dollars per month if he has the time and skills to dedicate to such a venture. Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Freelance Writing category, check our popular posts, or choose a related post below:20 Words with More Than One SpellingDriver License vs. Driver’s LicenseDouble Possessive