Tuesday, April 29, 2008
Sunday, April 27, 2008
The quality of the video images and the sound is excellent. I enjoyed the use of classical music in the score, especially in an opening montage showing closeups of the various interview subjects. These were faces with a lot of character.
My whole family enjoyed it.
Order it here.
Friday, April 25, 2008
Wednesday, April 23, 2008
Monday, April 21, 2008
It was interesting to watch the Pope's visit.
It was very windy again yesterday. Devil's Slide was closed in the morning, I expect because some signs got blown over.
Saturday, April 19, 2008
Friday, April 18, 2008
Thursday, April 17, 2008
Tuesday, April 15, 2008
Sunday, April 13, 2008
It had been warm for some days. I started wearing a lighter jacket to work on Thursday. Today we were at my mom's house for dinner. I was sitting with her in the kitchen and I heard the fog horns. The fog came in quickly.
I took the photo on 24-March-2008.
Friday, April 11, 2008
Wednesday, April 9, 2008
Monday, April 7, 2008
This morning when I was walking to work, there was a huge line of buses for the RSA Conference at Moscone Center.
Despite the game and the conference, traffic was reasonable on the way home.
Saturday, April 5, 2008
While serving as editor of Manufacturer and Builder Magazine, he wrote many articles, including the ones which gave this blog its name. In 1893 and 1894, he published a 23-part (!) memoir in the same periodical.
Here is the third part. He continues his discussion of an attempt to build a battery and electric motor that could power a lathe. Macedonio Melloni was an Italian physicist who studied the properties of heat. Antonio Pacinotti was an Italian physicist who improved the dynamo. Zénobe Gramme was a Belgian electrical engineer who created the first dynamo useful in industry.
Dr Van Der Weyde's comment that he considered the dynamo, "as the most lofty product of the combined ingenuity of the civilized human race," made me think of Henry Adams' comments in The Education of Henry Adams in the chapter "The Dynamo and the Virgin": "...but to Adams the dynamo became a symbol of infinity. As he grew accustomed to the great gallery of machines, he began to feel the forty-foot dynamos as a moral force, much as the early Christians felt the Cross."
I like the Doctor's comments about how much the world had changed for the better during his life and how much he expected it to change after.
The image comes from the first installment, in the February, 1893 issue.
Reminiscences of an Active Life.
BY DR. P. H. VAN DER WEYDE.
From Manufacturer and Builder, Volume XXV, Number 4. April, 1893
Career as an Electrician (continued from p. 59). -- Everything went on favorably for awhile (at least as far as superficial examination appeared to show), and the electric motor had become the admiration of all friends who saw it, especially after the man had been instructed how to shunt out, by means of a piece of wire, any cell which appeared doubtful, and when, by a galvanometric test, it proved defective, to substitute a freshly charged cell, without interrupting the current, and consequent motive power.
I had long before made an astatic galvanometer, of which the magnetized needles were made of pieces of watch spring, while the coil was made of fine wire covered with silk, which at that time was not in the ordinary trade, but had to be made to order in one of the European capitals, as well as the copper wire.
As the city of my residence had no industries of this character, it often taxed my ingenuity to procure what I wanted. Thus, for instance, I had saved for a long time the very fine wire covered with silk which I obtained from my mother, whose lace collars and caps were, according to the fashion of that time, stiffened with such wire, which at every washing had to be taken off and renovated.* Such stiffenings for lace were at that time sold in fancy stores of all widths desired; they were imported from England, and very well made. I bought some of the new material, disentangled its complexity so as to obtain the straight separate wires, and made several galvanometers, which rendered me great service for more than sixty years, and do so still. One of them was so sensitive that if I coiled up one end of the conducting wire into a little ball, heated this in an alcohol lamp, and touched it with the other end of the wire, which was cold, a deviation of the needle showed the existence of a current. This interesting little experiment was not original, but found by me in one of the Italian scientific periodicals. It was due to Melloni, who has made himself famous by his thermo-electric pile, which is the most delicate, and, in fact, the only instrument for the detection of slight differences of temperature in small bodies.
The apparent success of my motor was, however, a delusion and a snare. This became apparent when at last the great point, which lies at the bottom of all enterprises, was considered -- namely, the question: Does it pay?
Wages were low in Europe, especially at that time, and always much lower than here, while the materials consumed in the battery -- zinc and acids cost much more there than they do here now, thanks to the great improvements of manufacturing processes which have taken place. The result was that the most simple calculation of the cost of the battery showed that its maintenance was considerably more than the wages of the man, and then, very naturally, the idea was conceived to furnish the fly-wheel with a handle, and let the man turn the crank. This was found to be a very much more profitable arrangement, saving as it did the great cost of oxidizing the zinc and renovating the zinc plates, and the still more considerable cost of acids, salts and other substances which had also been tried, in order to find which of them was the best suited for the intended purpose.
Then I came openly forward and published an account of my experience, for the benefit of my co-laborers in the same field, of which the sub stance was this: "To my co-laborers on the great electric problem of the day: As long as we have no cheaper source of electricity than what we can obtain from voltaic batteries, it is of no use to make electric motors, because their cost of maintenance surpasses that of steam some fiftyfold, and even considerably more. Zinc, a product of art, costs much more than coal, while coal, a product of nature, costs only the labor of mining and transportation. Next comes the oxidation of the zinc, which is the source and origin of the electric current, and can only be obtained by expensive acids, or solutions of salts, or their equivalents, which, in fact, cost again as much as the zinc, or even more, while coal for its oxidation consumes only the natural atmospheric oxygen, which costs nothing."
The ultimate outcome of the experience obtained was published in detail in a scientific weekly published in Haarlem, Holland (entitled Algemeene Konst en Letterbode), March 15, 1844, in which I proved that in steam we have a cheap and powerful agent, while electricity is expensive and weak. I closed my communication with the following prophetic remark: "But how to obtain cheap and powerful electric currents is a question about which nothing is known at present. For its solution, the application of an entirely new, and, as yet, unknown principle will be required."
It took thirty more years of study and experimentation to find this entirely new principle.
Pacinotti, in Italy, started, in 1878**, the discovery of the new principle which I suggested, by inventing a motor with a continuously-wound coil, in which the current was intended to flow, and did flow, steadily in the same direction without interruption, or commutators for reversing the direction, which before that time was the only method known; and he stated in his description that if his motor was rotated by mechanical power with sufficient velocity, it would produce an electric current. He did not try this, but Gramme, in France, did, and the Gramme dynamo was born, which was the impulse to the construction of nearly infinite varieties of dynamos, which are still daily increasing, and cause those who are initiated in the details of their construction to watch with much interest every new step forward, and say to himself, What next?
I consider the dynamo as the most lofty product of the combined ingenuity of the civilized human race. The principles on which it is based developed themselves slowly from the experimental labors of the great men (too numerous to name here) who spent their lives in the investigations of the properties and laws of the great natural power of which the knowledge and application belong entirely to the nineteenth century. We leave, indeed, a glorious legacy to the generations of the twentieth century; let them proceed on the paths which the present generation has pointed out, and the results will be such as no one has the capacity to conceive.
Grateful as I am not to have been born a century earlier, when, without steam power, without steam navigation, without railroads, without gas, without electric telegraphy, heating, illumination, and electric transportation, the world was scarcely worth living in, still I envy the children of to-day who will be able to see the results of what those colossal dynamos will accomplish, which we now see constructed; and I regret deeply that at a period when the world has reached a point when the most startling and the most beneficial discoveries will be ripe for application, it will be time for myself and my contemporaries to leave the scene; but we trust that our posterity will progress in the same path that we have opened to lead humanity to the realization of the comprehensive word -- "Excelsior."
* The large collars seen in Queen Elizabeth’s portraits were stiffened in this way, and such collars were in her time much used even by gentlemen when in full dress.
** See the journal Nuovo Cimento.
Thursday, April 3, 2008
http://www.earlyaviators.com/ reports that he went on to fly in Mexico during the Revolution and lived until 1978.
This photo is from Aero and Hydro: America's Aviation Weekly, 03-February-1912.