Still another petrol-electric system is that invented by Mr Thomas. In this system, which is at the same time the simplest and most practical form of petrol-electric transmission, two dynamotors and an epicyclic gear are employed so that the electrical load is at no time greater than one half of the total load; consequently, the risk of a “burn out” of the windings, as the result of sudden and unforeseen periods of overload, is materially minimized.
Special Applications.—Amongst the special applications of the petrol-engined commercial vehicle is the motor fire-engine, which Has brought to the front in this branch several enterprising motor manufacturers, amongst whom Dennis Bros., of Guildford, Halley, of Glasgow, and Leyland, of Preston, are prominent. The general construction of the chassis closely follows the lines of other petrol vehicles of equal load capacity, but the gear-box tail-shaft is prolonged to the after-end of the machine, and is direct-coupled to the rotary member of a multistage centrifugal pump. In the Dennis fire-engine, the vacuum which is necessary in order to lift the water in the suction hose is obtained by means of priming the pump chamber, further assisted by a water ejector and a small water tank which is carried on the machine. This machine is shown in fig. 33, whilst fig. 34 shows the successful motor fire-engine built by Halley’s Industrial Motors, Ltd., of Yoker, Glasgow. In the latter machine, as also in the Leyland and other fire-engines which employ centrifugal pumps, the vacuum is created by means of reciprocating air pumps. These machines have given very satisfactory results in the hands of practical firemasters, in various parts of the United Kingdom and abroad. Merryweather and Shand-Mason, who were formerly builders, of steam fire-engines, now also build petrol-engined machines, these makers favouring reciprocating water pumps.
Other special applications of the internal-combustion motor are for grass mowing and rolling, and for road mending and rolling gravel paths, &c. One of the latter type of machines is shown in fig. 35. In this machine a petrol or paraffin engine drives a water-ballast roller through the medium of a clutch, a simple form of change-speed gear-box, and a single roller chain.
Fig. 37.—45 h.p. Thornycroft Military Oil Tractor.
The leading roller, by which steering is effected, is also filled with water, in order to obtain the dead weight necessary for rolling. Marshall, Sons & Co., Ltd., of Gainsborough, Thornycroft, of Basingstoke, and Broom & Wade, of High Wycombe, have also produced special machines for agricultural and military purposes, and one of the smallest tractors built by the first-named maker is shown in fig. 36. The engine is one of the two-cylinder type, consuming paraffin fuel, and driving the live back axle through a substantial gear-box and a final drive of the externally-toothed type. Such a machine is well below the weight limit for heavy motor-cars. Fig. 37 shows a more powerful oil tractor by Thornycroft. This machine is the same type which was so successful in the tractor trials promoted by the British War Department in March 1909. It is capable of hauling a gross load of seven tons practically anywhere, and even of lifting that load vertically by means of its winding cable. The engine has four cylinders, and the fuel may be paraffin, alcohol or crude oil. (E. S. S.)
MOTRIL, a town of southern Spain in the province of Granada,
at the foot of an offshoot of the Sierra Nevada and on the edge
of a rich alluvial plain, about 1 m. from the Mediterranean and
40 m. S.S.E. of Granada, with which it is connected by a good
carriage road. Pop. (1900), 18,528. The climate is semi-tropical,
and the vega or plain of Motril has been found peculiarly adapted
for the culture of sugar-cane and sugar-beet. In the district, and
especially at Salobreña, 3 m. west, there are numerous sugar-factories;
cotton is also grown and manufactured, and alcohol,
flour, soap, iron goods and cotton stuffs are among the other
industrial products. The neighbourhood is rich in zinc and
lead; and copper is also found. Motril itself is a port of the
second class, but the anchorage at Calahonda, 412 m. south-east,
is much better. Grapes, barley, esparto grass, dry figs, almonds
and zinc are exported.
MOTT, LUCRETIA [Coffin] (1793–1880), American reformer, was born at Nantucket, Massachusetts, on the 3rd of January 1793. She was descended on her mother’s side from Peter Folger, one of the first settlers of Nantucket, and the grandfather of Benjamin Franklin; her father’s ancestors, also, were among the first settlers of Nantucket. At thirteen she was sent to a Friends' boarding school, at Nine Partners, near
Poughkeepsie, New York, where James Mott (1788–1868), who like her was of old Quaker stock and whom she married in 1811, was then a teacher. In 1810 James Mott entered the employ of Lucretia’s father in Philadelphia, but the business was not successful and in 1817 Lucretia opened a small school under the care of the Pine Street Monthly Meeting, but gave it up a year afterwards and in the same year was recognized by the Friends as an “acknowledged minister.” Her husband had as early as 1822 espoused the cause of Elias Hicks against
the “Orthodox” Friends, and in 1827, when the Society divided,
Lucretia joined the Hicksites. Hicks’s teachings on slavery
had impressed both James and Lucretia; in 1830 James gave
up a lucrative cotton commission business that he might not
proht from the products of slave labour; and both took an
active part in the campaign against slavery. About 1840 Mrs
Mott also took up the cause of woman’s rights. On lecturing
tours she and her husband travelled as far west as Indiana and
into Maryland and Virginia. In 1848 she addressed the Anti-Sabbath
Convention in Boston, and with Elizabeth Cady Stanton,
whom she had first met in London in 1840, called a convention
“to discuss the social, civil and religious condition and rights
of women,” which met at Seneca Falls and passed a “Declaration
of Sentiments,” modelled on the Declaration of Independence.
Her husband, who was prominent among the founders
of Swarthmore College (1864), died in Brooklyn, New York, on
the 26th of January 1868; and Mrs Mott died on the 11th of
November 1880f near Philadelphia.
See James and Lucretia Mott: Life and Letters (Boston, 1884), edited by their granddaughter, Mrs Anna Davis Hallowell.
MOTT, VALENTINE (1785–1865), American surgeon, was
born at Glen Cove, New York, on the 20th of August 1785.
He graduated at Columbia College, studied under Sir Astley Cooper in London, and also spent a winter in Edinburgh. After acting as demonstrator of anatomy he was appointed professor of surgery in Columbia College in, 1809. From 1811 to 1834 he was in very extensive practice as a surgeon, and most successful as a teacher and operator. He tied the innominate artery in 1818; the patient lived twenty-six days. He performed a similar operation on the carotid forty-six times with good results; and in 1827 he was also successful in the case of the common iliac. He is said to have performed one thousand amputations and one hundred and sixty-five lithotomies. After spending seven years in Europe (1834–1841) Mott returned to New York and founded the university medical college of that city. He translated A. A. L. M. Velpeau’s Operative Surgery, and was foreign associate of the Imperial Academy of Medicine of Paris. He died on the 26th of April 1865.
