628 



PHYSICS, PROGRESS OF, IN 1898. 



cades erected along the railroad were admirably 

 constructed, consisting of double rows of trenches 

 running diagonally on both sides of the track, pro- 

 tected by thick earthworks topped with stones, 

 provided with loopholes, and in some instances 

 having sheet-iron roofs. These intrenchments 

 were stoutly defended from front attacks, and 

 were only taken by being successively enfiladed, 

 whereupon the defenders disappeared into the woods, 

 only to make a stand at the next line. South of 

 Manila, the "Monadnock" bombarded Paranaque. 

 The gunboats of light draught got near enough to 

 shell Malabon, which was thereupon hastily evacu- 

 ated. The town was left in ruins, and was not oc- 

 cupied by the Americans, who pushed on toward 

 Malolos. Beyond Marilao Gen. MacArthur's troops, 

 on March 27. encountered a body of Aguinaldo's 

 choicest soldiers, who were sent down from Malo- 

 los to contest the advance of the Americans upon 

 the rebel capital. There was a stubborn fight 

 which was ended by a brilliant charge of the South 

 Dakota regiment, putting the enemy to flight, The 

 railroads were damaged as much as possible by the 

 natives when they evacuated the country ; not so 

 much, however, that they could not be quickly re- 

 paired. Already supply trains were running to 

 Marilao. The bridges over the rivers took a longer 

 time to restore, but in a few days they were re- 

 placed. The gunboats entered the Bulacan river 

 and did great execution in the battle near Marilao. 

 The Filipinos left nothing but charred ruins in 

 the towns that they abandoned. Such were the or- 

 ders of Gen. Luna, their commander in chief. On 

 March 28 Gen. MacArthur attacked Bulacan, which 

 was defended by fresh troops from Malolos. While 

 Gen. Otis's brigade captured this city, Gen. Hale on 

 the right took Guirguintc. In three days the Amer- 

 ican army lay before Malolos. After a short bom- 

 bardment of the trenches, the infantry advanced, the 

 Nebraska and South Dakota troops flanking the 

 position on the right, the Tenth Pennsylvania in the 

 center, and the Twentieth Kansas and First Montana 

 Infantry and the Third Artillery on the left. The 

 enemy vacated the trenches after offering a slight 

 resistance. It was found that the main Filipino 

 army had retreated to Calumpit two days before, 

 leaving a small rear guard to make a feint of oppo- 

 sition and to set fire to the town when the Ameri- 

 cans made their appearance. The American army 

 rested in the deserted Filipino capital before making 

 any further advance. When a reconnoitering party 

 appeared at Calumpit Aguinaldo retreated to Bali- 

 nag. The total number of casualties in the encoun- 

 ters with the Filipinos from Feb. 4 to April 4 were 

 184 officers and men killed and 976 wounded. 



PHYSICS, PROGRESS OF, IN 181)8. Grav- 

 itation. Richarz and Krigar-Menzel (Wiede- 

 mann's "Annalen," LXVI, 177) have finished their 

 determination of the gravitation constant by means 

 of the balance, on which they have been working 

 since 1889. They find the constant to be 



This result lies between these of Poynting and Boys, 

 and is probably the best yet obtained. 



The Ether. Wien (ibid. July) notes that if the 

 ether is immovable a thin plate possessing different 

 radiating powers for heat rays on its two faces could 

 put itself into motion by virtue of the difference of 

 pressure on the two faces. It is possible, he thinks, 

 that the ether is carried along by the earth, but not 

 by bodies of small mass. (See also " Compressi- 

 bility," under " Mechanics," below.) 



Mechanics. Strength of Materials. Faurie 

 (Paris Academy of Sciences, Jan. 31) finds that test 

 pieces of metal subjected to longitudinal stress un- 



der certain conditions develop nodal points at equal 

 distances apart. The effects are not produced by 

 bending or torsion. 



Compressibility. Barus ("American Journal of 

 Science," October), in experiments on the compres- 

 sibility of colloids, finds that an aqueous solution of 

 gelatin or albumen has a low compressibility, and 

 that India rubber dissolved in ether has a high out-. 

 When the colloid was compressed by mercury the 

 meniscus would occasionally give way and a small 

 drop would be projected through the substance, the 

 colloid probably liquefying in front and being solidi- 

 fied behind the moving drop. Prof. Barus applies 

 this phenomenon to the problem of the motion of 

 material bodies through a solid ether. 



Deformation, Charpy (Societe Franaise de 

 Physique) finds that the deformation produced in a 

 metal by a given force depends on the time during 

 which the force acts. This is most noticeable with 

 lead and is still true of copper, though not in the 

 ordinary conditions of experiment. In the use of 

 copper cylinders to measure the force of a confined 

 explosive by their deformation, however, this fact 

 may interfere with the results. M. Charpy's exper- 

 iments show that the deformation produced by a 

 given charge is smaller the less the time of action. 

 The results of measurements with such cylinder 

 are thus too small and should be multiplied by a 

 coefficient somewhere between 1.1 and 1.2. 



Elasticity. Thurston ("Science,'' April 15), in 

 an investigation of the relations of stress to strain 

 in the case of India rubber, finds that in the early 

 part of the strain it behaves precisely like other 

 elastic substances ; then a reversed curve is described 

 and the rubber stiffens greatly, offering constantly} 

 increasing resistance until at last rupture takes 

 place without yielding by inelastic deformation at 

 any point of its course. The fracture is sharp and 

 sudden and the break is smooth and at right angles 

 to the line of pull. The highest load measured was 

 810 pounds per square inch. The author notes that 

 Prof. R. A. Fessenden's experiments on rubber and 

 other highly elastic substances indicate the existence 

 in them of two components, a hornlike substance 

 and a jellylike matter, in its pores. 



Torsion. Peddie (Edinburgh Royal Society, June 

 20) finds that calling the range of oscillation of a 

 twisted wire y and the number of oscillations x, 

 these are related in a manner shown by the equa- 

 tion y n (x-\- ) = b, where n, , b are constant for any 

 one experiment. He finds (1) that when the wire is 

 greatly fatigued n and b are independent of the 

 initial range, n becoming unity when the fatigue is 

 very great ; (2) that when n is unity b is absolutely 

 constant ; (3) that the period of oscillation does not 

 affect the results ; and (4) that the time of inward 

 oscillation over a given range exceeds that of out- 

 ward oscillation. He adopts a simple molecular ex- 

 planation of these facts. 



Oscillation. Schlichter (" Nature," Feb. 3) com* 

 pounds pendulum vibrations in three directions ;it 

 right angles by attaching a tiny electric lamp to the 

 bob of a Blackburn pendulum that vibrates in a hori- 

 zontal plane and photographing its path by a stere > 

 scopic camera attached to a pendulum that swings 

 about a horizontal axis. The result is viewod 

 through a stereoscope. 



Liquids. Jfi/tlrniilics. Knibbs (New Soiiih 

 Wales Royal Society, XXXI) has investigated the 

 flow of water in uniform pipes and channels ai d 

 finds that the formula- used generally by engineers 

 are defective. In a mathematical investigation he 

 finds that the slightest roughness on the inside ol a 

 pipe leads to unstable states of fluid motion reMilt- 

 ing in the formation of eddies. It is probable tint 

 the flow of water in anything but a mathematically 

 smooth pipe thus can not be rigorously treated by 



