Scientific.

Waikato Times, Volume XXVI, Issue 2113, 23 January 1886, Page 2 (Supplement)

Scientific.

Coppkr Telrgrapii Wires.— lt will be lemeinbered thai at the British Association meeting, Mr Pleece stated that in a trial of iron and copper telegraph wires of a length equal to the distance ! between London and Newcastle, the speed of transmission with copper was 414 words per minute, whereas iron gave 345 words. Mr Pluccc thought the gain of speed was due to a greater electric il anbseeplibility of copper as compared with iron. His opinion, according to Engineering, is borne out by Professor Hughes, who is at present engaged in investigating this phenomenon with the induction balance. Professor Hughes ] finds tiut copper is more sensitive, mole- 1 oularly speaking, to changes in an electric current than iron is. For example, he finds it impossible to balance a copper against an iron wire of exactly the same resistance in the Wheats tone bridge, until after a definite but very short time which the current takes to attain its) maximum in the iron wire. This effect, which is not noticeable with the ordinary galvanometer, is, in his opinion, not entirely due to the electrostatic capacities of the wires, but to some molecular inertia or peculiarity of their molecular construction. A Nkw Us? foe Toads. —The latest and most ingenious way of getting rid of roaches and water bugs we have heard of, is related of a citizen of Sohenectady, whose kitchen was infested with them. A servant, hearing that toads were an antidote, caught three ordinary hop toads and put them in the kitchen. Not a toach or water busr, it is stated, can now be found in the house. The toads have become domesticated, never wander about the house, and are so cleanly and inoffensive that there is no objection to their presence. Another use for toads is to employ them for insect destroyers in the garden. They are determined enemies of all kinds of snails and slugs, which it is well-mown can in a single night destroy a vast quantity of lettuce, carrots, asparagus, el 3. Toads are also kept in vineyatds, whe<*e they devour during the night Millions of insects that escape the pursuit of nocturnal buds, and might commit incalculable havoc on the buds and young shoots of the vine. In Paris toads are an article of merchandise. They are kept in tubs, and sold at the rate of two francs a dozen. — Scientific Amnricm. Curious Results. —Some time ago it was shown by Mr Bayley that when drops of various solutions are allowed to fall upon filter paper the salt which was in solution, in many cases, remained in the centre, and a water ring extended around it. Mr J. U. Lloyd has extended Bayley's experiments, and has observed the distances to which various subjects in aqueous solutions spread on pieces of blotting-paper, dipped into the solutions, before they are left behind by the water. Great differences were noticed in the length to which different salts thus travelled. Mixtures of silts were also examined, and in some instances it wrs found that one salt paraes on, while the other is left completely behind. Thus a solution of quinine and herberine sulphateswa^ capable of .being separated, owing 'to this fact ; the former salt pasaing on through the paper after the progress of the latter had quite ceased. Diluted sulphuric acid bohaved similarly, pure water alone passing onward. Unsuspected Effect of Steam. — One of the raosc peculiar freaks of heat noticed by the Philadelphia insurance inspectors was in a wooden box lined with cement, which was used for boiling cloth in pure water. On tearing away the box, what wa3 originally 3-inch pine plank was found to have been reduced to charcoal, or carbonized for two-thirds of its thickness from the inside. The box or tub coutaiaed water, boiled by introducing steani, and from some cause the wood was changed to the condition of charcoal by the heat of the steam. This case of the action of steam heat, says the Industrial World, although almost improbable, naturally attracts attention to (team pipes as a cause of fire. From the experience of those using steam, it is now regarded as unsafe to allow pipes to rest on wood. Electric'ty an© Calculating Machines.—Electricity has recently been applied to the working of calculating machines, by an enterprising American inventor. The record is shown on dials, somewhat in the same manner as on the street-car conductor's register, except instead of making nine motions to register nine units, one movement only is required, and the movement of the dials is effected, by electricity instead of by cogß. The perfection of the device is such that on the machine in the Massachusetts Census Office, in Boston, which has nine dials, the addition of one unit to the registered number, 999,999,999, sets all the dials at zero, so that if there was another dial the record would be 1,090,000,000.