325 



LOCKED JAW. 



LOG AND LOGLINE. 



are likely to be vitiated by various circumstances, and the results con 

 tested with angry feelings; for a man whose trade is that of making 

 safety-locks would not be very ready to acknowledge the vulnerabilit; 

 of his own productions. The best result of these contests has been 

 that all the best locks have been made still better than before, b; 

 additional securities suggested by the contests themselves. Mr. Hobb* 

 in 1853, picked a lock in a few minutes which had just won a prize 

 from the Society of Arts since which event it has been deemed better 

 to let the lock-makers fight their own battles, without any testimonials 

 or sanction from learned bodies. Mr. Denison has devised a lock in 

 which a handle suffices to shoot or lock the bolt, but the unlocking 

 cannot be effected except by the previous use of a very small key 

 an arrangement which he thinks likely to be useful in giving an 

 employer much control over his clerks and others in the use of the 

 lock. 



The usefulness of this series of controversies has also been shown 

 in the improvement of the manufacture of locks generally, both it 

 efficiency and cheapness. Messrs. Hobbs and Ashley have introducec 

 the American plan of manufacturing by machinery, ensuring both 

 rapidity and exactness to a degree not attainable by mere hand-work 

 and it can hardly be doubted that English manufacturers must ultimately 

 follow the same course. Mr. Price, of Wolverhampton, living in the 

 very centre of the lock-making district, states that down to 1856, 

 there was scarcely a machine of any kind used in the manufacture oi 

 locks and keys throughout the whole district. Wolverhampton makes 

 most of the good locks, Willenhall nearly the whole of the common 

 kinds ; but in the one place, as in the other, the operations are 

 almost wholly hand-work. The manufacture is mostly in the hands oi 

 small masters, each of whom works at the bench himself and employs 

 a small number of men and apprentices. The produce is sold to 

 the Wolverhampton factors or merchants; and many of the small 

 masters depend on the weekly receipts from the factors for the means 

 of carrying on the next week's operations. There are very few lock- 

 manufactories where the trade is conducted on anything like a large 

 scale. 



The principle and detail of modern lock-construction will be found 

 fully treated in Tomlinson's Cyclopwdia of Arts ;' in the ' Rudimentary 

 Treatise,' forming a part of Weale's Series ; and in Denison's Essay, 

 reprinted from the new edition of the ' Encyclopaedia Britannica;' 

 while Price's bulky volume (nearly 1000 pp.) on safes, locks, and keys, 

 is a storehouse of gossip on all parts of the subject. 

 LOCKED JAW. [TETANUS.] 

 LOCUS. This word, or the Greek TO'TOJ, signifying simply place, 

 was used by the first geometers to denote a line or surface over which 

 a point may travel, so as always to be in a position which satisfies 

 gome given condition. Thus, suppose it required to find the position 

 of a point at which a given line subtends a right angle : the answer is, 

 that the number of such points is infinite ; for that any point whatso- 

 ever upon the surface of a sphere which has the given line for its 

 diameter is such a point as was required to be found. This would be 

 expressed as follows : the locus of the point at which a given line sub- 

 tends a right angle, is the sphere described on the given line as a 

 diameter. If, however, the point were required to be in a given plane, 

 its locus would no longer be the whole sphere, but only that circle 

 which is the common section of the sphere and the given plane. 



The following assertions are really nothing more than common pro- 

 positions of geometry, stated in such a manner as to introduce the 

 term locus. (1.) The locus of the vertex of an isosceles triangle 

 described upon a given base is the straight line which bisects the base 

 at right angles, (2.) The locus of the vertex of a triangle which has a 

 given base and a given area is a pair of straight lines parallel to, but 

 on different sides of, the base. (3.) The locus of the vertex of a tri- 

 angle which has a given base and a given vertical angle, and which 

 lies on a given side of the base, is an arc of a circle of which the 

 given base is the chord ; and so on. 



The geometrical analysis of the Greeks depended much upon the 

 investigation of loci, and the method of using them will sufficiently 

 appear by one instance. Suppose, for example, it is required to de- 

 scribe a triangle of given area and given vertical angle upon a given 

 base. Laying down the given base, it is easy to draw the parallel 

 which is the containing line, or locus, of the vertices of all the triangles 

 which have the given area ; and aleo, upon the same side, the arc of 

 the circle which is the locus of the vertices of all the triangles having 

 the given vertical angle. If then the parallel and the arc of the circle 

 intersect, the point or points of intersection are obviously the vertices 

 of triangles which satisfy all the required conditions ; if they do not 

 intersect, the problem is impossible. When the locus of all the points 

 satisfying a given condition cannot be ascertained by elementary geo- 

 metry, and when this locus is therefore taken for granted, we have the 

 species of solution which was called mechanical. An instance of this 

 will appear in the article TBISECTIOX OF THE ANGLE. 



It is to be understood that no curve whatever is called the locus of a 

 point, unless any point whatsoever of that curve may be taken as the 

 point in question. Thus, if each of six points should satisfy certain 

 conditions, all lying upon a given circle, and if no other point of the 

 circle should satisfy those conditions, that circle would not be called 

 the locus of the points. 



LODGINGS, in the law of landlord and tenant, is applicable only to 



apartments let for habitation in the same house with another ; and 

 whether the apartments be furnished or no, the law is the same. 



The letting, as it comprises au interest in land, should satisfy the 

 29 Car. II. c. 3 4 by being in writing, and must, when produced in 

 court, appear to be signed at least by the party against whom it is pro- 

 duced. Such letting entitles the lodger, without express mention for 

 that purpose in the contract, to the use of all those conveniences which 

 are properly common to the inmates of the same house, and necessary 

 to the comfortable use of his apartments, such as door-knocker, door- 

 bell, water-closet, and the like, the withdrawal of any of which by his 

 landlord may be a ground of action for the lodger. 



During the term of occupancy, if any of the lodger's goods are lost 

 or stolen from the house, the landlord is not liable to make good the 

 loss, as an innkeeper would be, unless it appear that he was privy to 

 the wrong. On the other hand, if rent is in arrear to the superior 

 landlord he may distrain on the goods of the lodger found in the house, 

 notwithstanding no rent is due from him to the inesne landlord ; the 

 lodger's remedy in that case being against his immediate lessor, by action 

 at law for the value of the goods taken. 



The term for which lodgings are let may extend to any period what- 

 ever, with this difference however as to the -instrument of contract, 

 that it must be by deed if the term exceeds three years by so much as 

 a day. Usually, however, such apartments are let for a portion of a 

 year merely it may be six months, a quarter of a year, a month, or a 

 week and the rent, if not a gross sum for the whole period, may be 

 stipulated as payable by the week, month, or other convenient period. 

 If it appear by the contract, taken as a whole, that it was for a period 

 absolutely, the tenancy expires with the end of the time, and there is 

 no necessity for notice to terminate it. But if it appear that both 

 parties to the contract contemplated a continuing tenancy, terminable 

 by either on giving the usual notice, it then becomes a question what 

 notice must be given. It is by no means certain that a weekly tenant 

 is bound, in the absence of usage or contract, to give any notice what- 

 ever of his wish to end the tenancy ; in London he must give a week's 

 notice, but that depends on the custom. Some text-writers have 

 inferred that monthly, quarterly, or half-yearly tenancies are only 

 terminable by a notice of equal length with the tenancy. No doubt 

 such a notice would be sufficient, and it is the safer course to adopt 

 when convenience will allow. But in the absence of any contract 

 between the parties, it does not appear but that a month's notice, 

 terminating with the end of the period, would suffice to determine a 

 tenancy for any shorter time than a year. Where a person hired 

 furnished apartments for three months, and a receipt was given for the 

 rent payable for the whole period, but at the end of the time he 

 continued still to occupy, it was held that the jury might infer from 

 these circumstances that the tenancy was continued afterwards from 

 week to week. 



The 7 & 8 Geo. IV. c. 29, 45, protects the property of those who 

 let lodgings from the dishonesty of their tenants by making it felony 

 for the person in occupation to steal or appropriate any chattel or 

 fixture allowed to be used in any house or lodging. 



On this subject see further Woodfall, Landlord and Tenant. 



LOG and LOGLINE. The apparatus by which the velocity of a 

 ship's motion through the water is measured. If at any moment a 

 piece of wood, or other light substance, be thrown out of a ship while 

 sailing, as soon as it touches the water it ceases to partake of the ship's 

 motion ; the ship goes on, and leaves it behind. If then after a certain 

 interval, say of half a minute, the distance of the vessel from the 

 Joating body be accurately measured, the rate of the ship's motion 

 through the water will be ascertained ; we do not say the actual rate 

 of the ship's going, but only that of its motion through the water, 

 because in many cases currents exist, and the wood itself is carried 

 along ; consequently the true rate cannot thus be known. 



This is the principle of the log : in practice the log is a flat piece 

 of wood, generally of the figure of a quadrant, loaded with lead on 

 ts arc, to make it float upright; to this is attached a line about 150 

 : athonis long, divided into equal lengths by little pieces of knotted 

 ;wine rove into it. These divisions begin about twenty or thirty yards 

 Tom the log, where a piece of red rag is usually fastened, in order to 

 show the place readily. All the line between the log and the rag is 

 jailed the stray line, and is of course omitted from the account. When 

 ;he log is thrown into the sea, which is done from the lee quarter of 

 ;he vessel, the log-line, by the help of a reel on which it is wound, is 

 'mmediately veered out, at least as fast as the ship sails ; as soon as the 

 cd rag leaves the reel, a half-minute glass is turned, and when the 

 sand is all run down, the reel is stopped. Then by measuring the 

 quantity of line run out, the distance sailed by the vessel in half a 

 minute is known, and by calculation its rate of going per hour. There 

 are various ways of dividing the line, the most usual of which is to 

 )lace the knots at distances of 50 feet from each other; now as 120 

 ,imes half a minute make an hour, and 120 times 50 feet make almost 

 a geographical mile, so many knots will run from the reel in an experi- 

 ueut as the vessel sails miles in the hour ; from this comes the expres- 

 ion of a vessel's sailing so many knots an hour meaning miles. Fit'ty- 

 >ne feet would be more accurately 120th part of a mile than 50 feet ; 

 but it is found practically that the ship's way is always a little inr" 

 ban that given by the log, arising from the circumstance that the line 

 a unavoidably pulled in some degree, and the log is consequently 



