|
Title: |
1880's Portrait- George H. Corliss |
|
Source: |
Eminent engineers 1906 pgs 110-121 |
|
Insert Date: |
4/16/2011 5:03:41 PM |
The name of Watt easily takes the place of first importance in the history of the steam engine—and probably the name of George H. Corliss would, by general consent, be given the second place. The importance of his inventions, and the excellence of his engineering achievements, is remarkable when we consider how little his inheritance and his early associations contributed to that end.
His father was a country physician—rather -noted for his surgical skill, which probably explains the mechanical instincts of his son George.
George was born in 1817 at Easton, Washington County, New York. He had a good country school education, and attended an academy at Carleton, Vt., for a time. In after years he related that he studied the elements of algebra while watching with a gun, for a woodchuck to come out of his hole. In 1837 he was clerking in a country store at Greenwich, N. Y., during which time an indication of his mechanical and executive ability showed itself. A spring freshet carried away the only convenient bridge. The local builders declared it impossible to erect even a temporary bridge for weeks to come. Young Corliss constructed an emergency bridge in ten days at an expense of only fifty dollars. This country store was in connection with one of the early cotton factories, and part of his work was to measure the cloth from the mill. It was a place of considerable responsibility, for young Corliss apparently had the entire charge of this and of selling all sorts of goods "on account." The next year he opened a country store of his own, but soon tired of it and sold out in less than a year.
Up to this time he had not seen the inside of a machine shop, and had no especial interest in that direction. It must have been very soon after, however, that he became interested in the possibility of constructing a sewing machine. He invented one and secured a patent in 1842. This was some years before Howe secured his patent. Corliss' device passed needles and thread through in opposite directions at the same time. To perfect this invention and to arrange for the construction, Corliss went to Providence in 1844. The Company to whom he went— Fairbanks, Bancroft & Co.—then doing a machine and engine business, were not long in recognizing his talent, and in persuading him to drop for a time his sewing machine, and enter their employ as a draftsman on engine designs. Within a year he was admitted to the firm, and within two years he had made the invention that revolutionized the construction of steam engines. Corliss was at this time, 1846, only 29 years of age. In 1848 he entered into a partnership under the name of Corliss, Nightingale & Co., and this company built the first engine embodying these improvements. This company was incorporated in 1856 as The Corliss Steam Engine Co. His original patent was dated 1849, but was re-issued in 1851 and again in 1859.
Hitherto all engines were controlled by a throttle valve that could only be varied in its operation by hand. As such a valve was necessarily some distance from the cylinder, the waste of steam was considerable, and it was impossible to operate it quickly enough to cut off steam during a part of a stroke. Mr. Corliss' invention was the combination of a regulator with a liberating valve gear and sliding valves. It did away with the wasteful throttle valve, placed the valves close to the cylinder, automatically opening and closing them, within limits, at any point of the stroke, thus allowing the steam to be used expansively. The first one constructed was a beam engine with a diameter of 30 in., stroke of 6 ft. and indicated 260 H. P. It had four flat slide valves, the two upper for supply and the two lower for exhaust.
The transmission was by rods and toothed segments from a central disc operated by a Crank and rod from an eccentric on the engine shaft. The cut-off was controlled by a trip operated from the governor and adjustable within limits at pleasure and automatically by the governor. When the catch was thrown out the valves were closed by weights with a dash pot to prevent excessive jar. This device permits the valve motion to act rapidly while opening and closing a port, and yet to move slowly in approaching the port and after it is well opened, thus securing ample port openings, permitting full admission and very slight frictional resistance. The construction of this engine was followed by two others of the same size and all were so successful that land was purchased and extensive works erected.
The second type substituted cylindrical for flat slide valves, which have since been characteristic of all of the Corliss valve gear. They were first used on a horizontal engine built in 1850.
The third type was designed in 1851 or 1852. It has cylindrical valves operated by rods from the central reciprocating disc. The trips were the well known "Crab Claw" and weights were used to close the valves.
This was the type first known in Europe and was the starting point for all later variations. In 1858 he invented a fourth valve gear which was not patented, and which is now seen in what is known as the Harris-Corliss type. The difference was in the manner of tripping the cut-off and the working of the valve lever.
A fifth type was exhibited for the first time at the Paris Exhibition of 1867. The fundamental construction was the same, but in detail the mechanism was entirely new. The most noticeable innovation was the substitution of springs for weights in closing the valves. This was really patented as early as 1859 but became generally known only after the Paris Exhibition.
A sixth form was designed in 1874 and 1875. The valves were closed by atmospheric pressure, weights or springs being no longer used. The reciprocating disc was centrally placed, but the operating rods were mounted in pairs, using two pins, instead of four, as formerly.
There was a seventh variation also but it was relatively unimportant, except that the disengagement was more exact and certain.
In 1880 an eighth valve-gear was designed and put on the market. This is known as the "wrist-lever type" of valve-gear.
Mr. Corliss anticipated the demand for higher piston speeds and saw that this would necessitate larger port openings, in order to get the highest efficiency from the steam. To get the full benefit of the larger port openings, it was necessary to operate the steam and exhaust valves much more rapidly than in the valve-gears in general use. This he accomplished by his improved wrist-lever type of gear, which he designed and built in 1885 and 1886. This, without question, was the best and most efficient Corliss type of valve-gear and is still exclusively used on the Corliss engines built at the original Corliss Works.
This invention of the automatic cut-off was a far reaching improvement. It so approved itself that the Corliss principle is seen in a majority of the steam engines built since his day. It was found to be extraordinarily satisfactory and economical. Mr. Corliss himself had such faith in it from the beginning that he did not hesitate to accept in payment for his engines a proportion of the guaranteed savings in coal consumption. Some of his guarantees seemed wildly extravagant, but he was always able to do better than he promised, and usually to his financial advantage.
Mr. Phillips, an old associate of Mr. Corliss, gives several instances of such guarantees:
"In 1855 he put an engine and boilers into the James Steam Mill at Newburyport, Mass., the price for engine and boilers to be five times the amount of coal saved in one year. The old engines, which were 24 x 48 (condensing developing about 180 H. P.) used on an average for the five years preceding Mr. Corliss' contract, 10,483 lbs. of coal per day, and were fair examples of the engines in use before Mr. Corliss' time.
"The new engines were found to use but 5,690 pounds per day, making a saving in a single year of $3,946.84, coal being reckoned at $6.00 per ton, making the total price paid to Corliss & Nightingale for a 180 H. P. condensing engine and boilers, $19,734.22."
"In 1856 a new engine was put into the Ocean Steam Mills in Newburyport, Mass., Mr. Corliss agreeing to take the old engines (which previous to this were considered by the owners first-class machines) and the saving of fuel in two and one-half years, or the sum of $3,000 cash. The Mill Company decided (having doubtless in mind the experience of their neighbor, the James Steam Mill) to pay the $3,000, a wise decision, as the saving amounted to that in two years."
"In 1852 a new engine was put into the rolling mill of Crocker Brothers & Co., in Taunton, Mass., guaranteeing to do one-third more work than the old engine was doing, and when five tons of coal was used per day, but two tons should be used to do the same work. Forfeit $1.00 per pound for every pound per day used above that amount. Another contract which sounds hazardous but which shows the faith which Corliss and his partners had in the engine, was that made with the Washington Mills at Gloucester, N. J., wherein they agreed to put in an engine of about 200 H. P. for the sum of $7,100.00 and forfeit $5,000.00 for each ton per day of coal above four tons which should be used in driving the mill. This contract was entered into knowing that about nine tons per day were used with the old engines."
This type of engine was particularly valuable to cotton and other mills where regularity of speed was essential. In spinning, especially, it was necessary to have an even speed. If the speed increased it resulted in broken thread. If it decreased it resulted in diminished production. The control was so sluggish, with the old type of engines, that the engines were run at a comparatively slow speed, in order that they could be throttled before they reached so high a speed as to be disastrous. The Corliss engine could be safely speeded to the highest rate permissible, without danger of racing; so effective was the regulation that a variation of work from 60 H. P. to*360 H. P. within a minute did not perceptibly affect the speed of the engine.
Probably the engine that brought Mr. Corliss the most notice was that built for the Centennial Exhibition. It would not be considered large in these days, but at that time it was counted extraordinarily large. Mr. Corliss was one of the original members of the Executive Committee. He suggested that they secure a single engine to furnish all the power necessary for the exhibition, but the others thought it a too hazardous undertaking, but later—after being unable to make satisfactory arrangements otherwise—they accepted Mr. Corliss' proposal and authorized him to construct such an engine. The engine had two upright cylinders 3’ 4 7/8” in diameter, with ten feet stroke. The beam was 27' between centers and weighed twenty tons, and was suspended 30 feet above the floor. The connecting rods were 24 feet long. The fly wheel was 29' 10" in diameter, two feet face and had 216 teeth. The pinion was 9' 1 1/2" diameter with 72 teeth. The crank shaft was 18 inches in diameter. The cylinders were double jacketed. The entire engine weighed over 600 tons. They ran on 30 pounds pressure, the shaft making 36 revolutions, and could develop 2800 H. P., although they were called upon for only about 1000 H. P.
It was placed in the center of Machinery Hall and ran without a hitch from beginning to end. Its starting and stopping marked the hours of opening and closing the exhibition. The engine was built in nine months and 26 days at a very large expense to Mr. Corliss above the amount received from the management of the Exhibition. It attracted the attention of every one, not only for its imposing and beautiful design, but for the excellent workmanship and its silent, regular running. It seemed to mark the acme of all the wonderful engineering works gathered together from all the world.
As time passes a larger measure of credit is given to Mr. Corliss for his invention than was granted by some of his contemporaries. For fifteen years after he began construction, his road was beset with legal difficulties. His patent was granted in 1849, and almost immediately he was opposed by owners of patents granted to Frederick E. Sickels in 1842 and 1845. Both sides engaged the best lawyers in the country, and every charge and counter-charge was bitterly contested.
Mr. Sickles gained his experience in marine engine construction, and very unwisely limited his patented claims to lifting, tripping and cushioning puppet valves. Corliss claimed the same for slide valves. Sickels devised a water dash pot to cushion his valves. Corliss devised an air cushion to prevent the weight that closed the valve from slamming.
Sickels' invention enabled him to cut off the steam at any point of the stroke, but this cut off was adjustable only by the hand of the engineer, and according to his judgment. Corliss' invention enabled him to cut off the steam, up to half the stroke, automatically, by the nice precision of the governor.
Asa Gray, President of the American Academy, said to him, on presenting the Rumford Medal, "Your engine embodies within itself a principle by which it appropriates the full, direct and expansive force of the steam and measures out for itself at each stroke, with the utmost precision, the exact quantity necessary to maintain the power required."
At the time he was with Nightingale, Mr. Corliss made art unsuccessful effort to apply his principle to the locomotive. A reference is made to it in the story of Alexander Holly, who was a draftsman at the time, with Mr. Corliss. There are reasons why the principle is not applicable to locomotive or marine engines, but for stationary and pumping engines, it is the first arid perhaps the best.
Mr. Corliss has invented other machines, notably a gear cutter, and his engineering ability is seen at its best in the large number of heavy, special machine tools which he designed for use at his engine works. They are being used to-day and hold their own in comparison with the most modern.
He built a number of large pumping engines and at one time engaged in a prolonged duel with the municipal grafters of Boston over a contract for sewage pumping engines. Mr. Corliss' proposition was for four engines having a guaranteed duty of 90,000,000 foot pounds, with boilers and all appurtenances, erected complete, for $180,000. Instead, a contract was placed which cost the city of Boston some $475,000. Mr. Corliss offered a guarantee of service far in excess of the favored choice, and to convince, offered to construct and operate at his plant, and at his expense, one of these engines, before proceeding with the contract.
In Mr. Corliss was a rare combination of conservatism with apparent venturesomeness, but his uniform success proved that his venturesomeness was not inconsistent with conservatism, but was based on knowledge and wise faith.
His engineering judgment was quite remarkable, and was well matched by an equally sound financial sense. For an inventor he was singularly under self control. He would doubtless have succeeded in any line of engineering, but having given his mind to engines, he refused to be drawn off to anything else. He was big enough to discern the possibilities of his department and to develop it to keep pace with his own growth.
Personally, he was always courteous, but somewhat reserved, and a strict disciplinarian, although genial and approachable to his friends and his humblest employee could always approach him with as much ease as any officer of his company and always feel assured of the same courteous attention.
One of his mottoes in business was, that "The highest standard of workmanship and the best materials of their respective kinds," were the only ones to be considered in the manufacture of his products. His sterling character was as much in evidence in private life as in business. His contributions to educational and charitable objects were not only most liberal, but always, in a marked degree, cheerfully given, although known only to his immediate family and the recipients. He was a devoted Christian in the highest sense of the term.
There is a story told that illustrates the benevolence of his character: At the time the workmen began to break ground for the pumping works at Providence, they disturbed a nest of young birds and Mr. Corliss had them move to another part of the grounds for a few days until the young birds were able to take care of themselves.
His clearness of mind is seen in his business correspondence, in law cases, in the brevity of his patent claims, and in the grasp of affairs generally.
He was highly honored by his townsmen, engineering associates and scientific associations.
He received a gold medal at the Paris Exhibition of 1867 in competition with over a hundred other engine builders. He received the Rumford Medal from the American Academy of Arts and Sciences in 1870. Although not an exhibitor, he was given a Grand Diploma of Honor at Vienna, in 1873, because his improvements were seen in so many of the different engines exhibited. The Institute of France gave him, in 1868, the Montyon prize and in 1886 the King of Belgium made him an officer of the Order of Leopold.
He was a state senator in 1868, 1869 and 1870 and a presidential elector in 1876.
He died in 1888.
Probably no single inventor since Watt has enhanced the efficiency of the steam engine as did he. When we consider the part that the steam engine has played in modern economics, this is a high distinction, indeed. |
|
1880's Portrait- George H. Corliss
|
|