Dec. 19, 1884.] 



KNOWLEDGE 



513 



colnmns. — F. G. As far as I can comprehend your requirements, 

 Goodero'a " Principles of Jlechanics," and bis " Elements of 

 Mechanism," and Sir J. Anderson's " Strength of Materials and 

 Structures" — all published in Longmans' "Text-books of Science," 

 — oipht to suit you. In fiction, read all Dickens's works, and those 

 of Charlotte Bronti', and "George Eliot." — M.D. I have not read 

 the work from which you quote, but, quite obviously, we can 

 simultaneously experience many sensations. A reply to the second 

 part of your query will best take the form of an illustration. I am 

 conscious of the optical sensation of a flickering light, of the tactile 

 one of warmth, of the aural one of a slight roaring sound, and the 

 sum of these states of consciousness make up my concept of a fire 

 burning in the grate by my side. — P. M-iCLEOD Yeabslev. I myself 

 literally no more believe in the existence of ghosts than I do in that 

 of the phoenir, or the hippogriff. Whether any of our readers may 

 have reason (good, bad, or indifferent) for being more credulous 

 I do not know. Several (second or third- hand) ghostly experiences 

 have already been recorded in these columns. — W. A. Cooper. A 

 map of the Moon appears on p. 223 of Vol. III. of Knowledge. — 

 ¥. W. Bellamy. England is not a bran-new country in process of 

 colonisation ; and I am firmly convinced that the plan you advocate 

 would be attended with the worst results. If all men were secured 

 absolutely against want, and if every one possessed a cultivated 

 intellect of the highest order, a Republic might quite conceivably 

 exist without the glaring and deplorable abuses which at present 

 appear inseparable (in practice) from that form of Government. 

 It will be time enough " to solve your problem " when " the highest 

 state of civilisation " has been attained. — J. Murray. You must 

 not be angry with me if I fail to grasp the idea that bodies " would 

 move from the up to the down by the only motion Nature has, 

 and that is Time." Nor, if I fail to form a definite conception of 

 your notion, " If our earth is passing through the deluge of solar 

 time, how easy it is to understand if it were passed through the 

 rest of the way in a sudden sort of way." I am in the same pre- 

 dicament, too, in connection with your hypothesis concerning " the 

 Earth's motion towards the Sun, which it reduces every lap of its 

 orbit itself and every other thing by the gain of one-quarter 

 day every year, which is the cause of such a winter now, 

 and such winters about ten thousand years ago, when tempera- 

 ture was about ten times as strong." You see, when I come 

 across such passages as these, I am myself apt to " pass through 

 the rest of" a letter "in a sudden sort of way." — Isiokia. The 

 earth rotates on her axis, in twenty-four hours, from west to east. 

 Suppose that the mean sun is on the meridian of Greenwich ; then 

 it will have been due south at every place 15°, or one hour, east of 

 the prime meridian one hour previously ; in other words, it will be 

 1 p.m. at all such places. Similarly, one hour west of Greenwich 

 it will be 11 a.m. Mark the result. It is noon on Dec. 19 at 

 Greenwich. Now let us travel eastward. It is 1 p m. (or there- 

 abouts) at Stettin, 2 p.m. at St. Petersburg, 3 p.m. at Aden, -1 p.m. 

 in the Aral Sea, 5 p.m. at Baikul, and so on, to 12 p.m , or midnight, 

 of Dec. 19, in the Friendly Islands, through which the 180th meri- 

 dian passes. Let us now, though, travel round the earth in a 

 westerly direction. One hour west of Greenwioh it is 11 a.m. ; two 

 hours, 10 a.m., at Cape Breton, 8 a.m. ; at Philadelphia, 7 a.m. ; at 

 New Orleans, C a.m. (all be it noted in the early morning of the 

 19th), so that by the time we reach our ISOth meridian in this 

 direction it is midnight on Dec. 18. Hence the navigator's change 

 of date. In answer to your second query, No. Only torpid. — 

 CiTiiot's. Purely a medical question, to be decided by personal 

 examination. — H. S. Dove. A 6-inch reflecting telescope would 

 be very much more effective than a 3-inch refractor; but the 

 reflector would cost about £30, and the achromatic £15. — Edward 

 Browm. I regret my inability to present you with the works you 

 ask for. Mechanics' Institutions, Workmen's Clubs, and now, in 

 your case, a Bible-class, from time to time appeal for gifts of books 

 by the conductor of this journal. Such have hitherto invariably 

 been refused, and I regret that no exception can be made in your 

 case. — T. Hcktley & Son. Delayed through being addressed to 

 the Editor instead of to the Publishers. — F. S. Donaldson. I know 

 nothing of the date of Charles Wesley's birth, beyond the fact of 

 its having occurred in the year 1708. — Science Teacher asks for 

 the address of Professor David Hrghes, the inventor of the micro- 

 phone, ic. — Dr. E. W. Prevost. "Thanks, but its length excludes 

 your contribution in the present crowded state of our columns. — 

 A. M. Triibner & Co., London. — C. B. Ajiding and D. Pitcairn. 

 Was unfortunately unable to avail myself of it. — T. May. I can only 

 feel gratified at your appreciation of it. 



(Buv I-nbrntors' Colmnn. 



So great is the numler of invenfinns noii: patented that many good 

 things are comparatirely lost in the croud. A succinct account, 

 therefore, by an Expert, of all inventions of really popular interest 

 atid itiilittf must he advantageous both to the public and the 

 Inx'cntor, enabling pei'Sons io hear of inventions already desiderated 

 by them, and thus acting reciprocally as a stimulant on supply 

 and dirmand. 



SANITARY TRAPS. 



The Engineer notes that about 1 per cent, of all the gas used in 

 New York, or about 55 millions of cubic feet annually, is used in 

 thirty of the largest theatres. This, at 8s. per thousand, ought to 

 offer electricity a fine field. 



" TRAP.^i," as is well known, are often insanitary in a very serious 

 sense icdeed. Mr. William Henman, of 38, Bennett's Hill, Bir- 

 mingham, has invented what seem to be decided improvements in 

 sanitary traps. In this invention the outer arm of the trap is elon- 

 gated, funnel-shaped, and made in one piece, with, or attached to, 

 a length of vertical pijie, so that no " lodgment " is allowed for 

 sewer-gas. There are, moreover, no "made" joints, and thence great 

 security is obtained against the admission of sewer-gas into a 

 building. The traps may be of any suitable size, and be made of 

 iron, earthenware, or any suitable material. 



LACTO-GLYCOSE. 



Mr. G. Melun, of the Marlborough Works, Stafford-street, 

 Peckham, London, S.E., is the inventor and manufacturer of what 

 is claimed to be a very remarkable mi:k food for infants and 

 children. One of the features of this preparation appears to be 

 the entire absence of all farinaceous properties which do not con- 

 duce, contrary to some popular teaching, to infants' health. Starchy 

 foods, indeed, are not good for children, and the closer the approxi- 

 mation to milk itself the better. Mellin's Lacto-Glycose, may be, 

 indeed, looked upon, when dissolved in water, as a solution of 

 Mellin's food in cow's milk, with this difference — that the peculiar 

 organisation of the caseine in the cow's milk has been destroyed 

 simply by mechanical means, viz., by the prolonged stirring and 

 trituration of the cow's milk with Mellin's food during the process 

 of evaporation at a low temperature. The milk is obtained from 

 the best country sources, and as large quantities are always mani- 

 pulated, a certain average milk is obtained, which is, no doubt, 

 more stable in composition than milk from one cow, so often 

 recommended. It can easily be inferred how well adapted this 

 form of food must be for hot climates, where milk is generally 

 more or less in a state of decomposition, or on board ship, where 

 good milk cannot be obtained for the feeding of infants. 



AN AUTOMATIC BOLT AND AN UNPICKABLE DOOR- 

 LOCK. 



WiiXT is known as Hancock's Patent Invisible Automatic Bolt 

 and Unpickable Door-lock is an invention having for its object 

 improvements in fastenings for street and other doors and windows, 

 and other similar openings. In this invention there are three long 

 bolts, radiating from the centre to the circumference of the door. 

 One of these bolts, which may be called the main bolt, is placed in 

 a horizontal line with the lock of the door, and the other two bolts 

 are placed perpendicularly — one fastening into the centre of the 

 frame at the top, and the other into the pl-ite beneath. The handle 

 is fixed in the centre of the door, from which the bolts are worked 

 by means of a cog-wheel placed upon the spindle of the handle, and 

 acting upon a rack upon each of the several bolts. A slot cut into 

 each bolt, and which works backwards or forwards upon a stud, 

 holds the bolt firmly in gear against the cog-wheel. The mechanism 

 being inside the panels of the door, is out of sight, and the handle 

 itself, which is secured to a disc, can, if necessary (together with 

 the spindle and cog-wheel), easily be removed. 



Should it be considered desirable to retain the usual lock in 

 addition to Hancock's invention, an important feature in this 

 appliance consists of a slotted plate upon the main horizontal 

 bolt, which plate, being shot over the ordinary keyhole, renders the 

 lock unpickable. By turning a small key in the disc of the handle, 

 all the bolts can be thrown into or out of gear with the central 

 cog-wheel, which in turn forms also a rachet-wheel, to which a 

 catch, held in position by a spring, is attached, thereby holding the 

 bolts rigidly in position until released by means of a proper key. 



For asylums and other public institutions, theatres, b^nks, 

 strong-rooms, oSices and warehouses, as well as the doors of private 

 houses, the cabins of ships and yachts, and, indeed, for all purposes 

 where absolute security and safety are required, this invention is 

 obviously of the highest consequence, and will doubtless command 

 the attention its importance deserves. It is also applicable to 

 existing doors, and being exceedingly simple ia coastruction is not 

 likely, we think, to get easily out of order. 



